CVE-2026-89725 Linux CVE debrief

Who should care

System administrators and security teams responsible for Linux kernel-based systems should assess their exposure and apply remediation. Linux distributions and maintainers should review and update their packages to address this vulnerability. Security teams should monitor for potential exploitation attempts and verify the integrity of the system and surrounding memory.

Why it matters

CVE-2026-89725 is a high-severity vulnerability in the Linux kernel that allows for out-of-bounds write on RX overflow in the media: cec: stm32 module. System administrators and security teams should assess their exposure and apply remediation.

• Verify RX overflow handling in media: cec: stm32 module.
• Assess exposure of Linux kernel-based systems.
• Monitor for potential exploitation attempts.
• Apply remediation by updating to a fixed version.

Technical summary

The vulnerability is caused by the lack of a bounds check in the stm32_rx_done() function, which can lead to writing peer-controlled bytes into surrounding memory. The CVE record and source item provide details on the vulnerability, including its description, CVSS score, and affected versions. A Linux kernel vulnerability allows for an out-of-bounds write on RX overflow in the media: cec: stm32 module. This issue arises from the lack of a bounds check in the stm32_rx_done() function, which can lead to writing peer-controlled bytes into surrounding memory. The vulnerability is reachable in normal operation once the driver has probed and receiving is enabled, from the IRQ thread, without any local privilege. The

Defensive priority

High priority should be given to assessing exposure and applying remediation, as this vulnerability has a high CVSS score of 8.8 and can be exploited without local privilege.

Recommended defensive actions

• Assess exposure by checking if the system uses the affected module and if the version is prior to the fixed version.
• Apply remediation by updating to a fixed version of the Linux kernel.
• Monitor for potential exploitation attempts.
• Verify the integrity of the system and surrounding memory.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, CVSS score, and affected versions. However, the corpus does not establish specific versions that are fixed or fully verified exploitation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.