CVE-2026-89543 Affecting linux-6.12 package, versions <6.12.111-1~deb12u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.21% (10th percentile)

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  • Snyk IDSNYK-DEBIAN12-LINUX612-20506587
  • published5 Oct 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

NewCVE-2026-89543  (opens in a new tab)

How to fix?

Upgrade Debian:12 linux-6.12 to version 6.12.111-1~deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Debian. See How to fix? for Debian:12 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir

Normal client creation goes through rpc_setup_pipedir(), which records clnt->pipefs_sb, but the mount-event path in __rpc_clnt_handle_event() calls rpc_setup_pipedir_sb() directly and never refreshes that field. The umount path also removes the directory without clearing clnt->pipefs_sb.

After a late pipefs mount or any remount, rpc_clnt_remove_pipedir() compares the current superblock against a stale pipefs_sb pointer and skips cleanup, leaving pipefs dentries whose inode private data still points at a freed rpc_clnt, leading to a potential use-after-free during subsequent rpc_info_open() or rpc_show_info() calls.

Fix this by properly updating clnt->pipefs_sb upon mount events and clearing it during unmount or failure paths.

CVSS Base Scores

version 3.1