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CVE-2026-53034 Linux CVE debrief

A null pointer dereference vulnerability was found in the Linux kernel's af_unix and sockmap components. The vulnerability occurs when a socket's peer is not properly set up before its state is updated, allowing a BPF program to update the sockmap and cause a null pointer dereference. This issue arises from a race condition between the unix_stream_connect() function, which sets the socket's state to TCP_ESTABLISHED before assigning a peer, and the unix_stream_bpf_update_proto() function, which checks if the socket's peer is set before updating the sockmap. The vulnerability can be mitigated by applying the provided patches or by restricting BPF programs from updating sockmaps. The patches fix the vulnerability by adding a null check during proto update in unix_stream_bpf_update_proto().

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-24
Original CVE updated
2026-07-10
Advisory published
2026-06-24
Advisory updated
2026-07-10

Who should care

Linux kernel developers and maintainers, as well as users of Linux-based systems, should be aware of this vulnerability and take steps to mitigate it. Affected operators must review and apply patches or mitigations to prevent exploitation. Vulnerability management and security teams should prioritize patching and monitor for potential exploitation attempts. Platform administrators should ensure that Linux-based systems are updated with the latest security patches.

Technical summary

The vulnerability is caused by a race condition between the unix_stream_connect() function and the unix_stream_bpf_update_proto() function. The unix_stream_connect() function sets the socket's state to TCP_ESTABLISHED before assigning a peer, while the unix_stream_bpf_update_proto() function checks if the socket's peer is set before updating the sockmap. This can cause a null pointer dereference when a BPF program updates the sockmap. The vulnerability can be mitigated by applying the provided patches or by restricting BPF programs from updating sockmaps.

Defensive priority

High

Recommended defensive actions

  • Apply the provided patches to fix the vulnerability
  • Restrict BPF programs from updating sockmaps
  • Monitor for potential exploitation attempts
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability was reported by an unknown source and is described in the Linux kernel's official documentation. The provided patches fix the vulnerability by adding a null check during proto update in unix_stream_bpf_update_proto(). The CVE record was published on 2026-06-24T17:17:14.843Z and has not been modified since then. The vulnerability affects Linux kernel versions and can be exploited by BPF programs that update sockmaps.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-06-24T17:17:14.843Z and has not been modified since then.