Link following in Linux kernel - CVE-2026-80663
Published: August 28, 2026
Vulnerability identifier: #VU146139
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-80663
CWE-ID: CWE-59
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to overwrite an attacker-chosen file.
The vulnerability exists due to improper link resolution in isst-daemon pidfile handling when opening a pidfile from a fixed path under /tmp. A local user can pre-create a symlink at that path to overwrite an attacker-chosen file.
The issue occurs when a daemon instance is run as root.
Affected software
Linux kernel
How to mitigate CVE-2026-80663
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
External References
- https://git.kernel.org/stable/c/19ffeb30fdfce63f8d6aca71bcdddb3f69d46278
- https://git.kernel.org/stable/c/607af438e6430893a822964c841a1994b33acccc
- https://git.kernel.org/stable/c/72a07abc6b9046f07a08bba353cad7667bcc9dce
- https://git.kernel.org/stable/c/905493a6338c82a70da16f86e0a6215db5a3d73d
- https://git.kernel.org/stable/c/db938eb9a3c1317596c28e94413b33426508d51b
- https://git.kernel.org/stable/c/e8adac69d1bdf035ef97cc914e845acd4ef08e28