VulnerabilityPublished 25 Sep 2026Updated 19 Oct 2026

CVE-2026-97522: Linux kernel · mptcp: fix bad accounting in __mptcp_subflow_push_pending()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in f3ef03357396d4b147d8e76c75fb612c2f264ffc : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 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 f3ef03357396d4b147d8e76c75fb612c2f264ffc, ddbf9f03c1cc7d5b86eebe7c2beea0db4286d354, dc054821e639a2e14f1419436612db70b6af45fc +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 ≥ 0fa1b3783a17d75a4aa1651a18ede041ffca5750, < f3ef03357396d4b147d8e76c75fb612c2f264ffc	Fixed in f3ef03357396d4b147d8e76c75fb612c2f264ffc
LinuxLinux	Affected ≥ 0fa1b3783a17d75a4aa1651a18ede041ffca5750, < ddbf9f03c1cc7d5b86eebe7c2beea0db4286d354	Fixed in ddbf9f03c1cc7d5b86eebe7c2beea0db4286d354
LinuxLinux	Affected ≥ 0fa1b3783a17d75a4aa1651a18ede041ffca5750, < dc054821e639a2e14f1419436612db70b6af45fc	Fixed in dc054821e639a2e14f1419436612db70b6af45fc
LinuxLinux	Affected ≥ 0fa1b3783a17d75a4aa1651a18ede041ffca5750, < a0a64525f3414268ed4b1945a1dc690aa974dd4f	Fixed in a0a64525f3414268ed4b1945a1dc690aa974dd4f
LinuxLinux	Affected ≥ 0fa1b3783a17d75a4aa1651a18ede041ffca5750, < 9781fa35d9f7a87a83115acd3a88bc9ce35b5407	Fixed in 9781fa35d9f7a87a83115acd3a88bc9ce35b5407
LinuxLinux	Affected =6.6	Fixed in–

AI-suggested

The issue is fixed in the Linux kernel versions identified by the provided commit hashes. Users should apply these patches or upgrade to a kernel version that includes these fixes to resolve the vulnerability.

Description

A vulnerability in the Linux kernel's multipath TCP (mptcp) implementation was fixed to correct improper accounting in the __mptcp_subflow_push_pending() function. The flaw involved updating copied byte counters even when the __subflow_push_pending() call failed, potentially causing mismatches in push call accounting.

Impact

The vulnerability could cause incorrect accounting of data transmission in multipath TCP subflows, potentially leading to data inconsistency or protocol state mismatches. No information is provided about exploitation in the wild or direct security impact such as privilege escalation or denial of service.

Summary

CVE-2026-97522 addresses a bug in the Linux kernel's mptcp subsystem where the __mptcp_subflow_push_pending() function incorrectly updates copied byte counters despite errors from __subflow_push_pending(). This could lead to inconsistent accounting of data pushed on subflows. The issue has been resolved by ensuring that byte counters are not updated if __subflow_push_pending() returns an error. The fix is included in specific Linux kernel commits identified by their hashes.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 13:44 UTC

Technical details

References

Community reviews

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