CVE-2025-40187: net/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce()

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-11-12 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: net/sctp: fix a null dereference in sctp_disposition sctp_sf_do_5_1D_ce() If new_asoc->peer.adaptation_ind=0 and sctp_ulpevent_make_authkey=0 and sctp_ulpevent_make_authkey() returns 0, then the variable ai_ev remains zero and the zero will be dereferenced in the sctp_ulpevent_free() function.

Affected products

Linux kernel: 4.17 — fixed in 6.18

How to fix

Upgrade to a fixed version: Linux kernel 6.18. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/025419f4e216a3ae0d0cec622262e98e8078c447
https://git.kernel.org/stable/c/1014b83778c8677f1d7a57c26dc728baa801ac62
https://git.kernel.org/stable/c/2f3119686ef50319490ccaec81a575973da98815
https://git.kernel.org/stable/c/7f702f85df0266ed7b5bab81ba50394c92f3c928
https://git.kernel.org/stable/c/badbd79313e6591616c1b78e29a9b71efed7f035
https://git.kernel.org/stable/c/c21f45cfa4a9526b34d76b397c9ef080668b6e73
https://git.kernel.org/stable/c/d0e8f1445c19b1786759ba72a38267e1449bab7e
https://git.kernel.org/stable/c/dbceedc0213e75bf3e9f9f9e2f66b10699d004fe

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