Medium severity · published Oct 21, 2026
CVE-2026-78116
Double free of an RTIO submission in the Broadcom AFBR-S50 sensor driver data-evaluation error path
New
5.2
CVSS
0.2%
EPSS
No
On KEV
Description
The Broadcom AFBR-S50 time-of-flight sensor driver double-completes an RTIO submission when sensor data evaluation fails. In data_ready_work_handler() (drivers/sensor/broadcom/afbr_s50/afbr_s50.c), a non-STATUS_OK return from Argus_EvaluateData() calls handle_error_on_result(), which finalises the request with rtio_iodev_sqe_err(), but execution then fell through to the tail of the function and finalised the very same struct rtio_iodev_sqe a second time with rtio_iodev_sqe_ok(). Unlike the other error branches in the same function, this one did not return.
Both completion helpers reach rtio_executor_done() in subsys/rtio/rtio_executor.c, which returns the submission to the pool via rtio_sqe_pool_free() and, for streaming (multishot) submissions, also releases the RX buffer with rtio_release_buffer(). The second completion therefore reads a freed rtio_iodev_sqe, pushes the same mpsc node onto the submission queue while it is already on the pool free list — splicing the two lists together — and re-submits the freed request so the next measurement is written through an already-released buffer. For one-shot submissions it emits a spurious success completion carrying stale userdata and frees the same pool entry twice.
The failure branch is driven by sensor conditions rather than by host software. The vendor API documents statuses such as ERROR_ARGUS_BIAS_VOLTAGE_REINIT and ERROR_ARGUS_LASER_MONITOR_INACTIVE as transient results of harsh ambient light, so a party in front of the optical sensor can provoke the invalid-data condition without any physical contact with the board or any software access; SPI transfer errors reach the same branch. In releases before the payload.Status check was dropped, ordinary sharp distance transitions in the sensor's field of view were sufficient.
Impact is corruption of the RTIO submission pool and mempool bookkeeping: aliased submissions, writes through released buffers, and duplicate completions delivered to the application. The attacker does not control the corrupted content, so the practical consequence is memory corruption and loss of availability on devices that instantiate brcm,afbr-s50, rather than directed code execution. Only builds that enable this driver are affected.
CVSS vector
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Attack vector
Physical
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZE
zephyr · zephyrproject
4.3.0 before 4.5.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-78116
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-78116
github.com
https://github.com/zephyrproject-rtos/zephyr/commit/817e92c5184c0d64b8cc6537f4e42ce1e5b635f9
github.com
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-559f-34rc-pgw2
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