SEPTEMBER 20, 2026
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Case File

CVE-2026-74735

UNKNOWN · CVSS N/A EPSS 0.16%

Source: NVD + CISA KEV + EPSS · Published 2026-08-26 · Last synced 2026-09-20

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's handling of L2TP tunnels and sessions, specifically in the `pppol2tp_proc_open()` and `l2tp_dfs_seq_open()` functions, where reference counting for tunnel and session objects is improperly managed. This can lead to a reference count leak if userspace closes certain files before reaching EOF, potentially resulting in resource exhaustion or denial of service. System administrators and developers managing Linux systems that utilize L2TP should prioritize patching this issue to prevent potential instability in their networking services.

CVE
CVE-2026-74735
Severity
UNKNOWN
CVSS
N/A
EPSS
0.16%
Linux

Original NVD 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.