VulnerabilityPublished 25 Sep 2026Updated 21 Oct 2026

CVE-2026-97615: Linux kernel · net: bridge: use option bits for CFM/MRP frame handlers

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in be5ead6552418d70df3a76b962ccd6ed78a31fb5 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in be5ead6552418d70df3a76b962ccd6ed78a31fb5, 994fd705ca498223d188024cde833739a9dddbd2, 260f99b355a44f6ce67971ebc9223b22c8f93957 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 25 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 90c628dd47ff4178f645b34938470bf43d02d123, < be5ead6552418d70df3a76b962ccd6ed78a31fb5	Fixed in be5ead6552418d70df3a76b962ccd6ed78a31fb5
LinuxLinux	Affected ≥ 90c628dd47ff4178f645b34938470bf43d02d123, < 994fd705ca498223d188024cde833739a9dddbd2	Fixed in 994fd705ca498223d188024cde833739a9dddbd2
LinuxLinux	Affected ≥ 90c628dd47ff4178f645b34938470bf43d02d123, < 260f99b355a44f6ce67971ebc9223b22c8f93957	Fixed in 260f99b355a44f6ce67971ebc9223b22c8f93957
LinuxLinux	Affected ≥ 90c628dd47ff4178f645b34938470bf43d02d123, < 42e033c8f30fd2923ccac3373ae70797e521dae1	Fixed in 42e033c8f30fd2923ccac3373ae70797e521dae1
LinuxLinux	Affected ≥ 90c628dd47ff4178f645b34938470bf43d02d123, < 7a49e6b16f36b8e085521699adbca3e321b6dd0c	Fixed in 7a49e6b16f36b8e085521699adbca3e321b6dd0c
LinuxLinux	Affected =5.11	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: net: bridge: use option bits for CFM/MRP frame handlers CFM and MRP register a global br_frame_type whose hlist_node is linked into the per-bridge frame_type_list when the first MEP/MRP instance is created. Enabling the protocol on multiple bridges therefore inserts the same node into multiple lists. Unregistering it on one bridge then corrupts list state belonging to another. These handlers can only be installed once per bridge, and they are uncommon. Track their per-bridge enable state with net_bridge option bits, which already live on the Rx hot cache line, and dispatch the matching handler directly from the receive path. Check both bits together first as an unlikely case. Remove the generic frame_type_list and br_frame_type helpers, which have had no other users since CFM and MRP were added. That shrinks struct net_bridge by 8 bytes and drops the list walk from the fast path. When neither protocol is compiled in, BR_CFM_MRP_OPTS is 0 and the compiler prunes the branch.

References

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