util-linux is core to nearly all Linux distributions; a local privilege escalation here can compromise servers/workstations across enterprises.
CVE-2026-76642
Local privilege escalation via libmount post-mount hooks in util-linux.
Is CVE-2026-76642 being exploited?
Not confirmed. CVE-2026-76642 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.18% probability of exploitation in the next 30 days.
How severe is CVE-2026-76642?
CVE-2026-76642 is rated High with a CVSS score of 8.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-76642?
Yes. A fix has been recorded for CVE-2026-76642. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-76642 affect?
CVE-2026-76642 affects util-linux (libmount) <=2.41.5 and 2.42.2, Most Linux distributions using affected util-linux. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-76642?
Upgrade util-linux to vendor fixed release; audit SUID files and mount hooks.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local attacker can run privileged post-mount hooks to inherit SUID bits or change inode permissions, achieving root escalation.
Immediate action required
- affected>= 2.39 and < 2.41.6
- affected>= 2.42 and < 2.42.3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.