CVE-2025-8842 NASM Netwide Assember preproc.c do_directive use after free
A local attacker can exploit a use-after-free flaw in the NASM assembler's preprocessor to potentially execute arbitrary code or cause a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-8842?
CVE-2025-8842 is a medium-severity use after free vulnerability in Nasm Netwide Assembler, published on 11 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability has been found in NASM Netwide Assember 2.17rc0. Affected by this issue is the function do_directive of the file preproc.c. The manipulation leads to use after free. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.
Which versions are affected by CVE-2025-8842?
It affects 1 product.
Products include Nasm Netwide Assembler.
How do I fix CVE-2025-8842?
No fix has been published for CVE-2025-8842 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-8842 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-8842 exists.
Other vulnerabilities in Nasm Netwide Assembler
Sources
Also known as AZL-66207, AZL-66227, DEBIAN-CVE-2025-8842, GHSA-55c8-h472-8xhp, UBUNTU-CVE-2025-8842.