In the Linux kernel, the following vulnerability has been resolved: l2tp: fix tunnel and session refcount leak on seq_file release In pppol2tp_proc_open() and l2tp_dfs_seq_open(), iteration state (pd->tunnel and pd->session) is kept in seq_file private data to allow iteration across multiple read() system calls. However, if userspace closes /proc/net/pppol2tp or /sys/kernel/debug/l2tp/tunnels before reading to end-of-file (EOF), any tunnel or session reference stored in pd->tunnel / pd->session is left un-dropped when seq_file private data is freed. Fix this by dropping any remaining pd->tunnel and pd->session references in pppol2tp_proc_release() and l2tp_dfs_seq_release() when closing the file.
History

Fri, 28 Aug 2026 18:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-753

Thu, 27 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-911
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 26 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-753

Wed, 26 Aug 2026 14:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: l2tp: fix tunnel and session refcount leak on seq_file release In pppol2tp_proc_open() and l2tp_dfs_seq_open(), iteration state (pd->tunnel and pd->session) is kept in seq_file private data to allow iteration across multiple read() system calls. However, if userspace closes /proc/net/pppol2tp or /sys/kernel/debug/l2tp/tunnels before reading to end-of-file (EOF), any tunnel or session reference stored in pd->tunnel / pd->session is left un-dropped when seq_file private data is freed. Fix this by dropping any remaining pd->tunnel and pd->session references in pppol2tp_proc_release() and l2tp_dfs_seq_release() when closing the file.
Title l2tp: fix tunnel and session refcount leak on seq_file release
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-26T14:36:49.352Z

Reserved: 2026-08-15T05:44:03.930Z

Link: CVE-2026-74735

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-26T15:16:52.057

Modified: 2026-08-26T15:16:52.057

Link: CVE-2026-74735

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-26T00:00:00Z

Links: CVE-2026-74735 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-28T19:30:16Z