Ubuntu Linux 6.8 GA retains the legacy AF_UNIX garbage collector but backports upstream commit 8594d9b85c07 ("af_unix: Don’t call skb_get() for OOB skb"). When orphaned MSG_OOB sockets hit unix_gc(), the garbage collector still calls kfree_skb() as if OOB SKBs held two references; on Ubuntu Linux 6.8 (Noble Numbat) kernel tree, they have only the queue reference, so the buffer is freed while still reachable and subsequent queue walks dereference freed memory, yielding a reliable local privilege escalation (LPE) caused by a use-after-free (UAF). Ubuntu builds that have already taken the new GC stack from commit 4090fa373f0e, and mainline Linux kernels shipping that infrastructure are unaffected because they no longer execute the legacy collector path. This issue affects Ubuntu Linux from 6.8.0-56.58 before 6.8.0-84.84.
History

Thu, 05 Mar 2026 21:30:00 +0000

Type Values Removed Values Added
References

Thu, 05 Mar 2026 19:30:00 +0000

Type Values Removed Values Added
Description Ubuntu Linux 6.8 GA retains the legacy AF_UNIX garbage collector but backports upstream commit 8594d9b85c07 ("af_unix: Don’t call skb_get() for OOB skb"). When orphaned MSG_OOB sockets hit unix_gc(), the garbage collector still calls kfree_skb() as if OOB SKBs held two references; on Ubuntu Linux 6.8 (Noble Numbat) kernel tree, they have only the queue reference, so the buffer is freed while still reachable and subsequent queue walks dereference freed memory, yielding a reliable local privilege escalation (LPE) caused by a use-after-free (UAF). Ubuntu builds that have already taken the new GC stack from commit 4090fa373f0e, and mainline Linux kernels shipping that infrastructure are unaffected because they no longer execute the legacy collector path. This issue affects Ubuntu Linux from 6.8.0-56.58 before 6.8.0-84.84.
Title Use-after-free of orphaned AF_UNIX in Ubuntu builds of Linux kernel
Weaknesses CWE-416
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:N/VI:H/VA:L/SC:H/SI:H/SA:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: canonical

Published:

Updated: 2026-03-05T20:11:41.411Z

Reserved: 2025-11-18T09:33:14.643Z

Link: CVE-2025-13350

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-05T20:16:10.730

Modified: 2026-03-05T21:16:12.963

Link: CVE-2025-13350

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.