Use-after-free in Linux kernel - CVE-2026-74581

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Main Vulnerability Database Vulnerabilities #VU144982

Use-after-free in Linux kernel - CVE-2026-74581

Published: August 24, 2026


Vulnerability identifier: #VU144982
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74581
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in fib6_rule_lookup() and fib6_rule_suppress() in the IPv6 routing rules handler when processing suppressed IPv6 route lookups. A local user can trigger route lookups involving a suppressing rule to cause a denial of service.

The issue occurs because a stale dst entry can be returned after the released route remains referenced in the lookup result.


Affected software

Linux kernel
Debian Linux
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
kernel (Red Hat package)
linux (Debian package)

How to mitigate CVE-2026-74581

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - addressed in versions 4.18.0-305.202.1.el8_4, 5.14.0-687.42.1.el9_8
linux (Debian package) - update to 6.12.105-1

External References

Related Security Bulletins