High

CVE-2026-89725 — media: cec: stm32: prevent out-of-bounds write on RX overflow

In the Linux kernel, the following vulnerability has been resolved: media: cec: stm32: prevent out-of-bounds write on RX overflow stm32_rx_done() appends each received CEC byte to rx_msg.msg[] using rx_msg.len as the write index, incrementing it on every RXBR (receive-byte-ready) interrupt without checking it against the buffer size: cec->rx_msg.msg[cec->rx_msg.len++] = val & 0xFF; rx_msg.msg[] is a fixed CEC_MAX_MSG_SIZE (16) byte array in struct cec_msg, and rx_msg.len is only reset on RXACKE/RXOVR or after a completed message (RXEND). The number of bytes received before RXEND is decided by the remote CEC device (it sets EOM), not by the driver. A peer that keeps sending bytes without ending the message drives RXBR repeatedly, pushing rx_msg.len past 16 and writing peer-controlled bytes out of bounds into the surrounding memory. This is reachable in normal operation once the driver has probed and receiving is enabled, from the IRQ thread, without any local privilege. The length check in the CEC core runs on the consumer side, after the byte has been stored, so it does not prevent the overflow. Bound the index in the driver before the store, as the other platform CEC drivers already do (e.g. tegra_cec), dropping the excess bytes of an overlong frame. Found by static analysis tool CodeQL.

Published Sep 11, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

—

No EPSS score.

Affects

Linux

CVSS base

8.8

High · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < f2499b720ea9b874d58770885c6c2e8445a8c3ef≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < 3df1a4026662121011187247897fe95fd84e8a3a≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < 37ac45f7d6e3a6a5dcf6452a0b7bad9a543e8344≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < 1b4fdefd788db990d1805feb5c7b2388de791ecd≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < c3edd7fb8e3692423a702705509947fc9c30b3d1≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < 0c260d3f97e52978a8c769bb095ac0901333a3ac≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < a85ce3b175615c2e13bc01e8a1b6b6b6910fde57≥ d69ae57453c80a2193bcdb3fd762efbec447eecf and < fb9dda38d4b9e90db07ed9a0ee2d35bf85494035 and 1 more version 4.13	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Adjacent

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.8	CVSS 3.1	High	2.8	5.9	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
8.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 8.8
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 11, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

8 on the record

git.kernel.org/stable/c/1b4fdefd788db990d1805feb5c7b2388de791ecd
NIST National Vulnerability Database
git.kernel.org/stable/c/3df1a4026662121011187247897fe95fd84e8a3a
NIST National Vulnerability Database
git.kernel.org/stable/c/0c260d3f97e52978a8c769bb095ac0901333a3ac
NIST National Vulnerability Database
git.kernel.org/stable/c/a85ce3b175615c2e13bc01e8a1b6b6b6910fde57
NIST National Vulnerability Database
git.kernel.org/stable/c/fb9dda38d4b9e90db07ed9a0ee2d35bf85494035
NIST National Vulnerability Database
git.kernel.org/stable/c/c3edd7fb8e3692423a702705509947fc9c30b3d1
NIST National Vulnerability Database
git.kernel.org/stable/c/37ac45f7d6e3a6a5dcf6452a0b7bad9a543e8344
NIST National Vulnerability Database
git.kernel.org/stable/c/f2499b720ea9b874d58770885c6c2e8445a8c3ef
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 13h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 13h
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No FIRST EPSS score.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-89725 is "media: cec: stm32: prevent out-of-bounds write on RX overflow", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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