vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2025-40240

sctp: avoid NULL dereference when chunk data buffer is missing

HIGH
7.5
CVSS Score
Published: December 4, 2025 at 03:31 PM UTC
Updated: October 19, 2026 at 07:10 PM UTC
1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel· Linux
90%
4.890017accff61ae89283ad9a51f9ac46ca01633fb
Vendor states this is fixed in 03e80a4b04ef1fb2c61dd63216ab8d3a5dcb196f (fixed)
Vendor states this is fixed in 08165c296597075763130919f2aae59b5822f016 (fixed)
Vendor states this is fixed in 441f0647f7673e0e64d4910ef61a5fb8f16bfb82 (fixed)
Vendor states this is fixed in 4f6da435fb5d8a21cbf8cae5ca5a2ba0e1012b71 (fixed)
Vendor states this is fixed in 61cda2777b07d27459f5cac5a047c3edf9c8a1a9 (fixed)
Vendor states this is fixed in 7a832b0f99be19df608cb75c023f8027b1789bd1 (fixed)
Vendor states this is fixed in 89b465b54227c245ddc7cc9ed822231af21123ef (fixed)
Vendor states this is fixed in cb9055ba30306ede4ad920002233d0659982f1cb (fixed)
Vendor states this is fixed in 4.8 (unaffected)
Vendor states this is fixed in 5.10.246 (unaffected)
Vendor states this is fixed in 5.15.196 (unaffected)
Vendor states this is fixed in 5.4.301 (unaffected)
Vendor states this is fixed in 6.1.158 (unaffected)
Vendor states this is fixed in 6.12.56 (unaffected)
Vendor states this is fixed in 6.17.6 (unaffected)
Vendor states this is fixed in 6.18 (unaffected)
Vendor states this is fixed in 6.6.115 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (8)

Source: cverecord
https://git.kernel.org/stable/c/61cda2777b07d27459f5cac5a047c3edf9c8a1a9
Source: cverecord
https://git.kernel.org/stable/c/08165c296597075763130919f2aae59b5822f016
Source: cverecord
https://git.kernel.org/stable/c/03e80a4b04ef1fb2c61dd63216ab8d3a5dcb196f
Source: cverecord
https://git.kernel.org/stable/c/4f6da435fb5d8a21cbf8cae5ca5a2ba0e1012b71
Source: cverecord
https://git.kernel.org/stable/c/cb9055ba30306ede4ad920002233d0659982f1cb
Source: cverecord
https://git.kernel.org/stable/c/7a832b0f99be19df608cb75c023f8027b1789bd1
Source: cverecord
https://git.kernel.org/stable/c/89b465b54227c245ddc7cc9ed822231af21123ef
Source: cverecord
https://git.kernel.org/stable/c/441f0647f7673e0e64d4910ef61a5fb8f16bfb82

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHLinux
Vector?

Quick Info

StatusDEFERRED

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card