CVE-2025-40204VulnerabilityPublished 26 Aug 2026Updated 12 Oct 2026

Security update for the Linux Kernel (Live Patch 1 for SUSE Linux Enterprise 16)

Affects SUSESource GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 07:57 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Aug 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 2026-10-26.

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 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.

ghsa-4xv3-7wp7-qjp7

What to do

AI-suggested

A security update (live patch) has been released by SUSE to fix this vulnerability by implementing constant-time MAC comparisons. Users should apply the live patch kernel update to mitigate this issue. Since this is an official fix, no additional mitigation steps are required beyond applying the patch.

Description

A timing attack vulnerability was found in the Linux kernel SCTP implementation used by SUSE Linux Enterprise 16. The issue involved a non-constant-time comparison of message authentication codes (MACs), which could allow attackers to infer sensitive information through timing analysis. The vulnerability has been fixed by updating the MAC comparison to use a constant-time helper function, preventing timing attacks.

Impact

The vulnerability could allow an attacker to perform timing attacks against the SCTP MAC comparison, potentially leading to information disclosure. However, no known exploits in the wild have been reported. The impact is limited to the SCTP protocol implementation in the affected Linux kernel versions.

Summary

CVE-2025-40204 describes a vulnerability in the SCTP implementation of the Linux kernel where MAC comparisons were not performed in constant time. This flaw could enable timing attacks that potentially leak sensitive information. SUSE addressed the issue by modifying the MAC comparison logic to use a constant-time helper function, mitigating the timing attack vector. The fix is included in a live patch for SUSE Linux Enterprise 16 kernel versions.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 12 Oct 2026, 22:36 UTC

Technical details

References

Community reviews

Related threats