CVE-2026-89725: Linux kernel · media: cec: stm32: prevent out-of-bounds write on RX overflow
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available that bounds the write index in the stm32 CEC driver to prevent out-of-bounds writes by dropping excess bytes. Users should apply the updated Linux kernel versions that include this patch. Since this is a kernel-level vulnerability, upgrading to a patched kernel release is the recommended remediation.
Description
A vulnerability in the Linux kernel's media: cec: stm32 driver allows an out-of-bounds write due to improper bounds checking on received CEC bytes. The driver appends each received byte to a fixed-size buffer without verifying the index, enabling a remote device to overflow the buffer by sending an excessively long message. This flaw can be triggered without local privileges once the driver is active. The issue was identified by static analysis and has been resolved.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89725 (opens in a new tab)
- git.kernel.org/stable/c/0c260d3f97e52978a8c769bb095ac0901333a3ac (opens in a new tab)
- git.kernel.org/stable/c/a85ce3b175615c2e13bc01e8a1b6b6b6910fde57 (opens in a new tab)
- git.kernel.org/stable/c/c3edd7fb8e3692423a702705509947fc9c30b3d1 (opens in a new tab)
- git.kernel.org/stable/c/fb9dda38d4b9e90db07ed9a0ee2d35bf85494035 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89725 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89725 (opens in a new tab)
- git.kernel.org/linus/fb9dda38d4b9e90db07ed9a0ee2d35bf85494035 (opens in a new tab)