CVE-2026-53004 Linux CVE debrief

Who should care

Linux kernel users and administrators should be aware of this vulnerability, especially those using SCTP with AUTH enabled. This vulnerability can lead to silent corruption of userspace data.

Technical summary

The sctp_getsockopt_peer_auth_chunks function in the Linux kernel's SCTP implementation does not properly validate the provided buffer size. Specifically, it checks if the buffer length is less than the number of chunks but does not account for the 8-byte header of the struct sctp_authchunks. This can lead to an out-of-bounds write when the caller provides a buffer that is too small. The vulnerability can be exploited by an unprivileged userspace caller that has opened a loopback SCTP association with AUTH enabled.

Defensive priority

High

Recommended defensive actions

• Apply the kernel patch that fixes the sctp_getsockopt_peer_auth_chunks function
• Review and update SCTP configurations to ensure proper buffer sizing
• Monitor systems for unusual behavior related to SCTP and AUTH chunks
• Perform a thorough review of system logs to identify potential exploitation attempts
• Implement additional monitoring to detect anomalies in SCTP traffic
• Verify that all SCTP associations are properly configured and validated
• Check for any unauthorized changes to SCTP configuration files

Evidence notes

The vulnerability was resolved in the Linux kernel. The fix aligns the peer variant of the function with its sibling, sctp_getsockopt_local_auth_chunks, which already had the correct check. Reproducer code confirms the vulnerability on affected systems.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.