CVE-2025-40240: Linux

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

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 products

• Linux Linux: from 4.8, before 5.4.301 (fixed in 5.4.301); from 5.5, before 5.10.246 (fixed in 5.10.246); from 5.11, before 5.15.196 (fixed in 5.15.196); from 5.16, before 6.1.158 (fixed in 6.1.158); from 6.2, before 6.6.115 (fixed in 6.6.115); from 6.7, before 6.12.56 (fixed in 6.12.56); …

Published 2025-12-04. Last modified 2026-07-30.