Skip to main content
VulnerabilityPublished Updated

CVE-2026-10678: zephyrproject zephyr · Memory-safety

Affects zephyrproject zephyrSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 8.1 High : upgrade to 4.4.2 or 4.3.1 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score
8.1High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 4.4.2, 4.3.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 21 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade zephyrproject zephyr to 4.4.2 or 4.3.1.

Affected software

ProductAffectedFixed in
zephyrprojectzephyrAffected
  • >=4.4.0 <4.4.2
Fixed in
  • 4.4.2
zephyrprojectzephyrAffected
  • >=4.3.0 <4.3.1
Fixed in
  • 4.3.1
GitHubzephyrpkg:github/zephyrOther threatsAffected
  • >=4.3.0 <4.3.1
  • >=4.4.0 <4.4.2
Fixed in
  • 4.3.1
  • 4.4.2

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The vendor has described a fix that defers buffer allocation until the first data byte, rejects zero-length packets, and moves bounds checks before writes. Until an official patch or update is available, restrict access to the I2C bus to trusted controllers to prevent malicious exploitation.

Description

The MCTP-over-I2C+GPIO target binding in Zephyr (subsys/pmci/mctp/mctp_i2c_gpio_target.c) processes pseudo-register writes from an I2C bus master byte-by-byte in mctp_i2c_gpio_target_write_received() without validating the order or the receive buffer. In the affected versions the MCTP_I2C_GPIO_RX_MSG_ADDR (data) handler dereferences and writes through b->rx_pkt without checking that the receive buffer was allocated: a controller that selects the data register and writes a byte without first sending the length register (which is what allocates the buffer) causes a write of an attacker-chosen byte through a NULL/unallocated mctp_pktbuf pointer (i.e. into a small attacker-advanceable offset above address 0), producing memory corruption or a hard fault. The same handler also performs a write-then-check bounds test, allowing a one-byte heap overflow at data[255] when more than 255 data bytes are sent. Because the I2C target callback is invoked with raw bytes supplied by whatever device is the bus master and the binding performs no authentication, a malicious or malfunctioning controller on the bus can trigger these without any prior protocol state, leading to memory corruption and/or denial of service on the target device. The vulnerable code was introduced when the I2C+GPIO target binding was added and shipped in Zephyr v4.3.0 and v4.4.0. The fix defers allocation to the first data byte with a NULL check, treats a missing length as a zero-sized packet rejected by libmctp, and moves the bounds check before the store.

References

Community reviews

Loading reviews…