CVE-2025-40240

In the Linux kernel, the following vulnerability has been resolved: sctp: avoid NULL dereference when chunk data buffer is missing chunk->skb pointer is dereferenced in the if-block where it's supposed to be NULL only. chunk->skb can only be NULL if chunk->head_skb is not. Check for frag_list instead and do it just before replacing chunk->skb. We're sure that otherwise chunk->skb is non-NULL because of outer if() condition.

Package Linux Kernel
Published 2025-12-04
Last modified 2026-04-15
Patch available
Yes

Affected versions

Linux kernel versions 4.8 and later are affected. Fixed in 5.4.301, 5.10.246, 5.15.196, 6.1.158, 6.6.115, 6.12.56, 6.17.6, 6.18 and their respective stable series.

Affected from
≥ 4.8
Fixed in
✓ 5.4.301 5.4.x ✓ 5.10.246 5.10.x ✓ 5.15.196 5.15.x ✓ 6.1.158 6.1.x ✓ 6.6.115 6.6.x ✓ 6.12.56 6.12.x ✓ 6.17.6 6.17.x ✓ 6.18

References

The following references provide additional information about CVE-2025-40240 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2025-40240?

    CVE-2025-40240 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 4.8 onward and has been patched in 5.4.301, 5.10.246, 5.15.196 and others. CVE-2025-40240 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2025-40240?

    Yes — CVE-2025-40240 has been patched. Fixed versions include 5.4.301, 5.10.246, 5.15.196 and others. If you are running Linux kernel 4.8 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-40240 actively exploited?

    No — CVE-2025-40240 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.