CVE-2026-18739 Popt-devel: popt-static: off-by-one in poptstuffargs
A local attacker can exploit an off-by-one error in the popt library to corrupt memory and potentially execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-18739?
CVE-2026-18739 is a low-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 4 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in popt, a command-line option parsing library. An off-by-one error in the poptStuffArgs function, when repeatedly called by a host application or through deep alias nesting, can lead to corruption of internal program data. This corruption could potentially enable a local attacker to execute arbitrary code if the host application then unsafely processes the altered data.
Weakness: CWE-787
Which versions are affected by CVE-2026-18739?
How do I fix CVE-2026-18739?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-18739 being exploited?
There is no known exploitation of CVE-2026-18739 in the wild and no public exploit code.
Sources
Also known as AZL-94508, AZL-94596, BELL-CVE-2026-18739, DEBIAN-CVE-2026-18739, ECHO-784f-603d-c633, GHSA-255r-gqmx-m2jm and 5 more.