TI-2026-52517 Aliases CVE-2026-74735 GHSA-wf96-m5fp-jh8c

l2tp: fix tunnel and session refcount leak on seq_file release

LOW 22Published 2026-08-26 · Updated 2026-10-30

Key facts

Attack vector: —
Privileges required: —
User interaction: —
Attack complexity: —
Impact type: —
Confidentiality · integrity · availability: —
Fix status: Partial Red Hat: 3 without a fix

No CVSS vector from any source. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

EPSS 0.00215 12th percentileScored 2026-11-08

Fix Partial Linux (Linux): 3.17, 4.17, 6.1.191 +5Red Hat: 3 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Linux	Linux	3.16.60 to before 3.17; 4.16.6 to before 4.17	3.17, 4.17	Patch available	CNA
Linux	Linux	4.17 and later	6.1.191, 6.6.160, 6.12.111, 6.18.53, 7.1.10, 7.2	Patch available	CNA

Linux VendorLinux Affected 3.16.60 to before 3.17; 4.16.6 to before 4.17 Fixed in 3.17, 4.17 Patch available CNA
Linux VendorLinux Affected 4.17 and later Fixed in 6.1.191, 6.6.160, 6.12.111, 6.18.53, 7.1.10, 7.2 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:o:linux:linux_kernel::::::::	—	—	Linux

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions — — ·Linux

Remediation

Fix · CNA Linux (Linux) Fixed in 3.17, 4.17
Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.111, 6.18.53, 7.1.10, 7.2

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Not affected: 2 products

Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7

Timeline

2026-10-02 Threatist record created from CVE-2026-74735
2026-10-03 Alias added: GHSA-wf96-m5fp-jh8c
2026-10-21 Fix available: Linux/[email protected], Linux/Linux@bd897e414451fb34dfdf08b31899180e5ab7149b · CNA
2026-10-21 1 new reference · CNA
2026-10-30 Fix available: Linux/[email protected], Linux/Linux@c38b723858a51d6ca4e56470b9f1087f23276772 · CNA
2026-10-30 1 new reference · CNA

References

Other 6

TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4

See all 21741 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences