High 7.8Published Jun 24, 2026

CVE-2026-53004sctp: fix OOB write to userspace in sctp_getsockopt_peer_auth_chunks

Updated under an hour ago (Oct 27, 2026, 4:10 PM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: sctp: fix OOB write to userspace in sctp_getsockopt_peer_auth_chunks sctp_getsockopt_peer_auth_chunks() checks that the caller's optval buffer is large enough for the peer AUTH chunk list with if (len < num_chunks) return -EINVAL; but then writes num_chunks bytes to p->gauth_chunks, which lives at offset offsetof(struct sctp_authchunks, gauth_chunks) == 8 inside optval. The check is missing the sizeof(struct sctp_authchunks) = 8-byte header. When the caller supplies len == num_chunks (for any num_chunks > 0) the test passes but copy_to_user() writes sizeof(struct sctp_authchunks) = 8 bytes past the declared buffer. The sibling function sctp_getsockopt_local_auth_chunks() at the next line already has the correct check: if (len < sizeof(struct sctp_authchunks) + num_chunks) return -EINVAL; Align the peer variant with its sibling. Reproducer confirms on v7.0-13-generic: an unprivileged userspace caller that opens a loopback SCTP association with AUTH enabled, queries num_chunks with a short optval, then issues the real getsockopt with len == num_chunks and sentinel bytes painted past the buffer observes those sentinel bytes overwritten with the peer's AUTH chunk type. The bytes written are under the peer's control but land in the caller's own userspace; this is not a kernel memory corruption, but it is a kernel-side contract violation that can silently corrupt adjacent userspace data.

CVSS: 7.8 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Jun 24, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 65b07e5d0d09c77e98050b5f0146ead29e5add32 before a132e199de69e2a45628aa8534df1bf5d44e1b6e; 65b07e5d0d09c77e98050b5f0146ead29e5add32 builds before 2b5a2c957c7769d40110f725cf23987fcef50d75; from 65b07e5d0d09c77e98050b5f0146ead29e5add32 before d45c7e99caf915b0f6c716bd8ffe9d45b9685761; from 65b07e5d0d09c77e98050b5f0146ead29e5add32 before d67fbc6dea5dbf7f46c618ebf65910a276078e20; from 65b07e5d0d09c77e98050b5f0146ead29e5add32 before 6849b995cda88a677bf08a05765d1db7905974fc; from 65b07e5d0d09c77e98050b5f0146ead29e5add32 before 70a089cc9590aa347a61e84434116ab74619e3c3; 65b07e5d0d09c77e98050b5f0146ead29e5add32 builds before 6bcf8fe4ef7967b22b814cbae9a57bbd3c853410; 65b07e5d0d09c77e98050b5f0146ead29e5add32 builds before 0cf004ffb61cd32d140531c3a84afe975f9fc7ea	CNA record
linux linux_kernel linux:linux_kernel	from 2.6.24 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.141; from 6.7 before 6.12.91; from 6.13 before 6.18.33; from 6.19 before 7.0.10	NVD

References

References

https://git.kernel.org/stable/c/a132e199de69e2a45628aa8534df1bf5d44e1b6e	patch
https://git.kernel.org/stable/c/2b5a2c957c7769d40110f725cf23987fcef50d75	patch
https://git.kernel.org/stable/c/d45c7e99caf915b0f6c716bd8ffe9d45b9685761	patch
https://git.kernel.org/stable/c/d67fbc6dea5dbf7f46c618ebf65910a276078e20	patch
https://git.kernel.org/stable/c/6849b995cda88a677bf08a05765d1db7905974fc	patch
https://git.kernel.org/stable/c/70a089cc9590aa347a61e84434116ab74619e3c3	patch
https://git.kernel.org/stable/c/6bcf8fe4ef7967b22b814cbae9a57bbd3c853410	patch
https://git.kernel.org/stable/c/0cf004ffb61cd32d140531c3a84afe975f9fc7ea	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.