RIOT-2026.07 "Quando omni flunkus, moritati" - Release Notes

View on GitHubThe changelog can also be found on GitHub.

RIOT is a multi-threading operating system which enables soft real-time capabilities and comes with support for a range of devices that are typically found in the Internet of Things: 8-bit and 16-bit microcontrollers as well as light-weight 32-bit processors.

RIOT is based on the following design principles: energy-efficiency, soft real-time capabilities, small memory footprint, modularity, and uniform API access, independent of the underlying hardware (with partial POSIX compliance).

RIOT is developed by an international open-source community which is independent of specific vendors (e.g. similarly to the Linux community) and is licensed with a non-viral copyleft license (LGPLv2.1), which allows indirect business models around the free open-source software platform provided by RIOT.

About this release

The 2026.07 release includes:

This quarter, RIOT gained an iPerf 2-compatible lwIP benchmarking example, improved hardware mocking on native, and new or improved support for several boards. The core also received a quality-of-life improvement with the new ACCESS() macro, thanks to @maribu.

RIOT now has basic Forth support through the ficl package, a lightweight, embeddable ANS Forth interpreter. NASA’s bplib package was also ported to RIOT, providing initial Bundle Protocol version 7 (BPv7) support for delay/disruption-tolerant networking (DTN). DTN is designed for challenged networks with intermittent connectivity or long delays, including space communications.

162 pull requests, composed of 284 commits, have been merged since the last release, and 12 issues have been solved. 32 people contributed with code in 99 days. 1478 files have been touched with 33798 (+) insertions and 16784 deletions (-).

Notations used below

+ means new feature/item
* means modified feature/item
- means removed feature/item

New features and changes

Core

core/clist: add insert function to keep lists sorted without resorting them (#22062)
core/lib/rmutex: add recursion depth handling (#22196)
core: allow annotations for compile time boundary checks (#22359)

core & examples: fix static tests warnings form github actions (#22217)

System Libraries

sys/checksum: add ACCESS() attribute() (#22372)
sys/isrpipe: add convenience helpers to improve sys/stdio (#22426)
sys/stdio_base: add ACCESS() attribute (#22370)
sys/string_utils: add ACCESS() attribute (#22368)
sys/crypto: add ACCESS() attribute (#22371)
sys/net/gnrc: add ACCESS() attribute and minor style fixes (#22367)

sys/checksum: minor improvements to algorithms (#22379)
sys/ecc: encode size information in signatures (#22373)
sys/isrpipe: fix blocking on zero bytes (#22389)
sys/psa_crypto: fix use of VLA and sprintf (#22129)
sys/random/fortuna: relicense under LGPL-2.1-only (#22390)
Split slipdev module dependencies (#22109)

Networking

examples/networking/misc/lwiperf: add application (#22286)
nimble/netif: add rssi to netif header (#22190)

drivers/[i]*: change license headers to SPDX format (#22164)
gnrc_netapi: warn about lost packets (#21216)
nimble/rpble: clear rpble ctx if DODAG is cleared (#22150)
sys/net/nanocoap: concretize debug message on malformed hdr (#22189)

Packages

pkg/ficl: new package (#22083)
pkg: Port NASA/bplib Package (#22091)

pkg/flashdb: bump to release 2.2.0 (#22194)
pkg: Use cargo home environment variable when set (#22258)

Boards

boards/common/native: expose mock saul GPIO pins (#22234)
boards/elecrow-crowpanel-esp32s3-rotary-128: add support (#22402)
boards/nucleo-g031k8: add support for STM32 Nucleo-G031K8 (#22354)
boards/nucleo-g031k8: Add timer support for the NUCLEO-G031K8 board. (#22404)
boards/nucleo-g031k8: add warning about reset configuration & add SVG pinout file (#22414)
boards/waveshare-esp32s3-touch-lcd-128: add board support (#22231)
boards: add seeedstudio sensecap t1000e support (#22267)

boards/arduino* & adafruit*: fix static tests warnings from github actions (#22183)
boards/msbiot: use stdio_rtt by default (#22050)
boards/nrf5340dk-app: Map out saul_gpio (#22290)
boards: fix static tests warnings from github actions (#22186)

CPU

cpu/lpc1768: add ethernet driver (#22305)
pkg/xipfs: add MPU memory isolation to file execution (#21760)

native: Remove unused variable (#22249)
sys/malloc_monitor: use hooks in native syscalls (#22349)

Device Drivers

drivers/gc9a01a: Implement device driver for the GC9A01 LCD controller (#22181)
drivers/qmi8658: Implement device driver for the QMI8658 IMU (#22138)

drivers/[j-o]*: change license headers to SPDX format (#22165)
drivers/periph: improve doc for I2C and UART peripheral driver (#22192)

Documentation

boards: add missing doc.md files (#22221)
cpu: Add missing doc.md files (#22291)
dist/tools: add static check for missing board doc.md files (#22240)
doc/guides: add remarks about other repos in Release Tutorial (#22214)
doc/starlight: Add SPDX headers (#22211)
doc/starlight: add supported CPUs (#22280)
doc/starlight: Integrate Boards (#22157)
doc: Add AI Policy (#22340)
drivers/periph/spi: add doc about multiple SPI buses (#22185)
.github/ISSUE_TEMPLATE: Add AI Declaration (#22412)

boards/nrf: update reset button documentation (#22364)
boards/stm32f429i-disc*: doc pages update (#22238)
doc/guides/installing: explain folder structure (#22233)
doc/guides: Extend documentation of submodules (#22325)
doc/guides: Remove mentioning of a hash tables feature (#22347)
doc/starlight: Fix boards and cpu links (#22296)
doc/starlight: Improve boards search style (#22262)
doc/starlight: Update to 0.39 (#22253)
doc: delete unmaintained roadmap (#22273)
doc: move Package Porting Tutorial to Guides and extend it (#22254)
treewide: Fix links in the docs and cleanup many boards (#22257)
GOVERNANCE.md: update process for inactive maintainers (#22339)
guides: Remove $ from code blocks and replace console with shell (#22300)
CONTRIBUTING.md: Remove $ characters in code blocks (#22299)
CONTRIBUTING: enhance section about squashing and rebasing (#22256)

Build System / Tooling

makefiles/docker: add user group ID to user command (#22212)
tools/zep_dispatch: topogen: allow to pass worldfile (#21779)

.github/workflows: reduce check-labels triggering (#22241)
build-system: write output to both SARIF and stdio (#22431)
dist/tools/vera++: drop style rule T010 (#22425)
tools/uf2: allow UF2_MOUNTPOINT override (#22210)

Testing

.github/workflows: Add first PR greeting (#22278)

.github/workflows: update actions to be Node24 compliant (#22274)

API Changes

build system: update terminology to control supported boards (#22114)

And 40 minor changes.

Deprecations

Removals (1)

dist/tools: Remove Deprecated git-cache Tool (#22197)

Bug fixes (40)

cpu/efm32: don’t add CMSIS/DSP include path explicitly (#22180)
sys/net/l2util: add missing bounds check to l2util_addr_from_str (#22356)
.github/workflows: Copy LLVM First Time Hack (#22312)
.github/workflows: only run Guide Deployment if Secret is configured (#22206)
.github: fix labeler.yml for labeler@v6 (#22276)
boards/xg23-pk6068a: remove HFXO_FREQ and LFXO_FREQ (#22295)
CONTRIBUTION.md: fix direct .md links (#22333)
core/msg: prevent thread from stalling indefinitely (#22193)
cpu/esp32: fix warning about conflicting symbols (#22341)
cpu/native/fs: fix stale errno reading in mount() (#22252)
cpu/native/socket_zep: fix frame checksum handling (#22317)
cpu/nrf5x_common: Cleanup of Vendor Header Makefile (#22202)
cpu/samd5x: provide a common OpenOCD script with PM fix (#22330)
dist/tools/benchmark_udp: fix macOS compatibility (#22260)
dist/tools/picotool: Temporary glibc bug fix (#22360)
dist/tools/riotboot_gen_hdr: use $BUILD_DIR to build in (#22225)
doc tree: fix verbatim block mismatch (#22328)
doc/doxygen: don’t set the checksum for DLCACHE for custom versions (#22416)
doc/rp2350: fix naming problems (#22121)
drivers/ads1x1x: fix UB assert on uninitialized dev in init (#22302)
drivers/at86rf215: always disable ACK filter when ending TX (#22218)
lwip: include lwip_udp if lwip_dhcp is used (#22337)
make: riot version code typo (#22315)
makefiles/docker: fix building Espressif boards when using podman instead of plain docker (#22348)
makefiles/tools: enhance miniterm path finding in serial.inc.mk (#22208)
makefiles/tools: select correct TTY by serial (#22215)
pkg/mpaland-printf: do not silently drop printing to stderr (#22282)
pkg/mpaland-printf: mark wrapper functions as used to fix LTO (#22184)
pkg/qcbor: disable HW FPU support for ESP32S2&ESP8266 (#22179)
Collection of bugfixes (#22580)
sys/can/isotp: various style and robustness fixes (#22250)
sys/clif: change use of const qualifier (#22204)
sys/include/atomic_utils: Fixed atomic bit “narrowing conversion” compile error (#22245)
sys/net/dhcpv6: guard against malicious packet length (#22322)
sys/net/gnrc_tcp: fix compilation on modern glibc (#22230)
sys/net/gnrc_tcp: minor style fixes (#22232)
sys/net/unicoap: properly handle options with value zero (#22222)
sys/test_utils/netdev_eth_minimal: guard data_len (#22301)
sys/{x,z}timer: minor bug fixes (#22393)
tests/net/ieee802154_hal: fix issues on native64 (#22187)

Known issues

6lo: RIOT does not receive packets from Linux when short_addr is set (#11033)
Address registration handling inappropriate (#15867)
app/netdev: application stops working after receiving frames with assertion or completely without error (#8271)
at86rf2xx: Dead lock when sending while receiving (#8242)
cpu/esp8266: Tracking open problems of esp_wifi netdev driver (#10861)
DHCPv6 client: Handling of NotOnLink incorrect (#20349)
dist/tools/sliptty/start_network.sh: IPv6 connectivity is broken on PC (#14689)
driver/mrf24j40: blocks shell input with auto_init_gnrc_netif (#12943)
drivers/at86rf215: Incorrect channel number set for subGHz (#15906)
DTLS examples cannot send message to localhost (#14315)
Emcute cannot create a double-byte name (#12642)
ethernet: Missing multicast addr assignment (#13493)
ethos: fails to respond to first message. (#11988)
ethos: Unable to handle fragmented IPv6 packets from Linux kernel (#12264)
example/gnrc_border_router cannot answer after some time (#19578)
examples/cord_ep: Dead lock when (re-)registering in callback function (#12884)
examples/gnrc_border_router: esp_wifi crashes on disconnect (#14679)
Forwarding a packet back to its link layer source should not be allowed (#5051)
gcoap example request on tap I/F fails with NIB issue (#8199)
gcoap: Suspected crosstalk between requests (possible NULL call) (#14390)
Global IPv6 addresses remain deprecated after receiving RA (#19846)
gnrc ipv6: multicast packets are not dispatched to the upper layers (#5230)
gnrc/ipv6: “invalid payload length” - corrupted IPv6 header when ENABLE_DEBUG=1 in mbox.c (#20390)
gnrc_border_router stops routing after a while (#16398)
gnrc_border_router: Kconfig and C disagree about number of addresses per interface (#19947)
gnrc_icmpv6_echo: flood-pinging another node leads to leaks in own packet buffer (#12565)
gnrc_ipv6: Multicast is not forwarded if routing node listens to the address (#4527)
gnrc_netif_pktq leaks memory (#17924)
gnrc_rpl: missing bounds checks in _parse_options (#16085)
gnrc_rpl: nib route not updated when topology / DODAG changes (#17327)
gnrc_rpl: takes unusually long time to start routing packets (#19147)
gnrc_sock_udp: Possible Race condition on copy in application buffer (#10389)
gnrc_tcp: gnrc_tcp_recv() never generates -ECONNABORTED (#17896)
ieee802154_submac: IPv6 fragmentation broken (#16998)
LoRaWan node ISR stack overflowed (#14962)
LWIP TCP Communication Error (#19676)
lwip, submac: deadlock on user transmission (#21843)
lwip_sock_tcp / sock_async: received events before calling sock_accept() are lost due to race condition. (#16303)
Missing drop implementations in netdev_driver_t::recv (#10410)
Neighbor Discovery not working after router reboot when using SLAAC (#11038)
net/unicoap: Message initialisers do not set .payload_representation (#22285)
netdev_ieee802154: Mismatch between radio ll address and in memory address (#10380)
nrf52: Not able to add global or ULA address to interface (#13280)
nrfmin: communication not possible after multicast ping with no interval (#11405)
ping6 is failing when testing with cc2538dk (#13997)
pkg/lwip: race condition (data loss) in async connection setup (#21874)
pkg/tinydtls: auxiliary data API does not work for async sockets (#16054)
Removing a TNT global address then adding a new one does not work (#20318)
samr30 xpro doesn’t seem to use its radio ok (#12761)
stale border router does not get replaced (#12210)
test/lwip: enabling both, IPv4 and IPv6, results in unexpected behavior (#18097)
tests/lwip: does not compile for IPv4 on 6LoWPAN-based boards. (#17162)
two nodes livelock sending neighbor solicitations back and forth between each other (#16670)
xbee: setting PAN ID sometimes fails (#10338)

Bug: timer setup can expose new callback or temporary timer state to IRQ handlers before setup finishes (#22410)
misc issues with tests/trickle (#9052)
periph/timer: timer_set() underflow safety check (tracking issue) (#13072)
periph_timer: systematic proportional error in timer_set (#10545)
saml21 system time vs rtc (#10523)
sys/newlib: gettimeofday() returns time since boot, not current wall time. (#9187)

at86rf2xx: Simultaneous use of different transceiver types is not supported (#4876)
cpu/msp430: GPIO driver doesn’t work properly (#9419)
drivers/at86rf215: not returning RX/IDLE after a while of operation with RPL/UDP (#21685)
drivers/at86rf215: The activation of the address match interrupt is missing in the at86rf215_reset function (#20505)
examples/dtls-wolfssl not working on pba-d-01-kw2x (#13527)
fail to send data to can bus (#12371)
mdt_erase success, but vfs_format resets board (esp32-heltec- lora32-v2) (#14506)
periph/spi: Switching between CPOL=0,1 problems on Kinetis with software CS (#6567)
periph: GPIO drivers are not thread safe (#4866)
PWM: Single-phase initialization creates flicker (#15121)
STM32: SPI clock not returning to idle state and generating additional clock cycles (#11104)
TCP client cannot send read only data (#16541)
tests/periph_flashpage: unexpected behavior on nucleo-l4r5zi (#17599)

examples/micropython: floating point exception while testing on native (#15870)
native not float safe (#495)
native: tlsf: early malloc will lead to a crash (#5796)
VFS_READ show correct data on every SECOND request only (#21470)
ztimer doesn’t wake up on native if the pm_layered module is used (#21083)

Failing tests on FE310 (Hifive1b) (#13086)
boards/hifive1: flashing issue (#13104)
cpu/sam0: flashpage write / read cycle produces different results depending on code layout in flash (#14929)
esp32-wroom-32: tests/netstats_l2 failing sometimes (#14237)
gcoap/esp8266: Stack overflow with gcoap example (#13606)
Get serial to work on ESP32-S3 chipset (#22527)
Interrupt callback function is instantly called on samd51 after setting it from within interrupt callback function (#19861)
MPU doesn’t work on cortex-m0+ (#14822)
newlib-nano: Printf formatting does not work properly for some numeric types (#1891)
periph_timer: Test coverage & broken on STM32F767ZI (#15072)
riscv: ISR stack is too small for ENABLE_DEBUG in core files (#16395)
stm32f7: Large performance difference between stm32f746 and stm32f767 (#14728)

Build dependencies - processing order issues (#9913)
build system: dependency files not updated when relevant environment variables change (e.g. BUILD_DIR) (#22531)
dist/tools/cppcheck/cppchck.sh: errors when running with Cppcheck 1.89 (#12771)
EXTERNAL_MODULE_DIRS silently ignores non-existent entries (#17696)
Kconfig: Unable to set Kconfig boolean variables with default true to false (#21785)
make: ccache leads to differing binaries (#14264)
make: use of immediate value of variables before they have their final value (#8913)
makefiles: make term does not print stderr output of child process. (#21808)

Other issues (86)

[nRF5x] periph_uart unreliable with GCC 9.3.1 (#21842)
[tracking] Bugs found by the peripheral selftest (#20071)
[Tracking] Failures found with testing on real hardware for release (#21882)
[Tracking] Fix failures of test-on-iotlab (#20791)
[TRACKING] sys/shell refactoring. (#12105)
[tracking] unnecessary use of floating point arithmetic (#19614)
_NVIC_SystemReset stuck in infinite loop when calling pm_reboot through shell after flashing with J-Link (#13044)
make term no longer works with JLinkExe v6.94 (#16022)
at86rf215 stops receiving until sending a packet (#19653)
backport_pr: Only works for when fork is in user (not in organization) (#18486)
benchmark_udp: hammering with low interval causes issues (#16808)
Board pinout diagram 404 on the guides site (#22353)
boards/esp32-wroom-32: tests/mtd_raw flakey (#16130)
boards/nucleo-f767zi: Switching clock sources causes the system to hang until power on reset (#22376)
Bug: adafruit-feather-nrf52840-sense is not reachable over USB after flashing with UF2_SOFTDEV=SD611 (#22448)
Bug: RTT/WDT callback setup can let overflow or early-warning IRQs use new callback state before setup finishes (#22411)
Bug: same-instance qdec_init() can let a pending QDEC IRQ use the new callback before setup finishes (#22406)
Bug: same-pin GPIO interrupt reconfiguration can let a pending IRQ use the new callback before setup finishes (#22407)
Bug: same-UART re-initialization can let a pending UART IRQ use the new callback before setup finishes (#22408)
Bug: UART reconfiguration can expose temporary callback or data-mask state to RX IRQ handlers (#22409)
Builds fail when different execstack options are around in objects (#18522)
Can’t build relic with benchmarks or tests (#12897)
CC2538-CC2592EM has a very weak transmit power (#17543)
cpp: Exception handling undefined (#17523)
cpu/stm32: fix STM32G4 flash writes failing after motor driver init (#22151)
cpu/stm32: some tests are failing on CM33 (l5, u5) (#17439)
doc/boards: information concerning access to RIOT shell (#17453)
doc/doxygen: reduce excluded errors (#22327)
doxygen: CSS hack to hide doc breaks on older browsers (#21312)
edbg: long lines flooded over serial become garbled (#14548)
examples / tests: LoRa tests fail on platforms that don’t support LoRa (#14520)
examples/gcoap: client broken (#19379)
Fixing warnings in RIOT static test (#22216)
flashing issue on frdm-k64f (#15903)
frdm-k22f failing tests/periph_flashpage (#17057)
frdm-k22f fails tests/periph_timer (#19543)
Freeze into semtech_loramac_send call (pkg/semtech-loramac) (#18790)
gcoap: gcoap_req_send and related should return negative for errors (#19393)
gnrc_ipv6_nib: Neighbor Solicitation ping-pong (#18164)
I2C Crashes Kernel on Raspberry Pi Pico (#21187)
ieee802154_security: Nonce is reused after reboot (#16844)
kconfiglib.py choice override of menuconfig bug (#19069)
LVGL tests produce unaligned code, fail to build (#20110)
lwip: drivers/at86rf2xx/at86rf2xx_netdev.c invalid state during TCP disconnect (#17209)
lwip: invalid state transition on ieee802154_submac users (#17208)
Making the newlib thread-safe (#4488)
mcuboot: flashes but no output (#17524)
MTD is confusing (#17663)
openDSME example application does not work reliable out of the box with nRF52840 MDK Dongles (#21922)
Order of auto_init functions (#13541)
periph_rtt: rtt_set_alarm() blocks IRQ for 80 plus usec on STM32 (#19520)
pkg/tinydtls: Multiple issues (#16108)
Potential race condition in compile_and_test_for_board.py (#12621)
RIOT is saw-toothing in energy consumption (even when idling) (#5009)
riotboot: ECC faults (eg. in STM32L5 or STM32WB) not handled gracefully (#17874)
rust-gcoap example is incompatible with littlefs2 (#17817)
Samr30/gpio: Erasing then write mux can generate spurious IRQ (#19993)
samr34-xpro: some tests failing (#19223)
sock_dtls: unable to send big messages (#17996)
spurious IRQs in periph_timer (#18976)
Starlight: “Supported Boards” and “Supported CPUs” Known Issues (#22203)
stdio UART input truncated (#21564)
stdio_ethos: infinite shell loop (#17972)
stdio_tinyusb_cdc_acm hangs with picolibc (#19277)
STM32 Nucleo boards improperly clocked (#19778)
STM32F4-discovery + mrf24j40 not working (#19711)
sys/psa_crypto/doc.md: needs rework after most of Kconfig was removed (#22329)
sys/riotboot: documentation issues (#11243)
sys/usb/usbus/cdc/ecm: interface thread blocked when connected host interface is down (#21098)
tests/lwip target board for python test is hardcoded to native (#6533)
tests/periph_flashpage: failing on stm32l475ve (#17280)
tests/pkg/relic is failing on samr21-xpro when built using llvm (#19903)
tests/pkg_libhydrogen: test fails on master for the samr21-xpro with LLVM (#15066)
tests/pkg_libschc: Failing test_reassemble_success_ack_always (#19445)
tests/riotboot does not pass on iotlab-m3 (#22006)
tests/test_tools: test fails while testing on samr21-xpro/iotlab-m3 (#15888)
tests: broken with stdio_rtt if auto_init is disabled (#13120)
tests: some tests don’t work with newlib lock functions. (#12732)
Tracking: callback state can become visible before pending IRQ state is cleared in several RIOT peripheral drivers (#22405)
tracking: failing tests with stdio_cdc_acm (#21231)
Types in byteorder.h need a cleanup (#14737)
USB identifiers with funny characters create mojibake (#17776)
usbus/msc: wrong error handling and behavior after usb reset (#19478)
Use of multiple CAN bus on compatible boards (#14801)
ztimer is incompatible with real-time requirements (#18883)
ztimer_periodic: occasional lockups (#21374)

There are 184 known issues in this release

Fixed Issues since the last release (2026.04)

boards/rpi-pico-2-*: fails to build in current docker (#22522)
Makefile.include: clean-intermediate deletes esp32_bootloader subfolder in bin/ (#22468)
dist/tools/zep_dispatch: compilation failure (#22465)
netbuf leak in lwip_sock_sendv() on netif-mismatch error path (#22422)
Bug: cpu/lpc23xx/periph/timer: old timer IRQ may call new callback after re-init (#22384)
current release .tar.gz fails to build examples (#22314)
cpu/native/socket_zep: Wrong FCS (#22313)
.github/workflows: First Time Contributor workflow does not trigger (#22311)
cpu/efr32: Invalid HFXO_FREQ after #22040 (#22283)
arduino-nano issue (#22156)
b-l072z-lrwan1: tests/ztimer_overhead: test failure (#19224)
scan-build errors found during 2019.07 testing (#11852)

12 fixed issues since last release (2026.04)

Acknowledgements

We would like to thank all companies that provided us with hardware for porting and testing RIOT. Further thanks go to companies and institutions that directly sponsored development time. And finally, big thanks to all of you contributing in so many different ways to make RIOT worthwhile!

More information

http://www.riot-os.org

Discussions

Join the RIOT Matrix room at: #riot-os:matrix.org
Join the RIOT Forum at: forum.riot-os.org
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License

The code developed by the RIOT community is licensed under the GNU Lesser General Public License (LGPL) version 2.1 as published by the Free Software Foundation.
Some external sources and packages are published under a separate license.

All code files contain licensing information