CVE-2026-65609 Out-of-bounds write in nnn
An attacker can execute arbitrary code or escalate privileges by tricking a user into loading a malicious session file in the nnn file manager.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-65609?
CVE-2026-65609 is a low-severity memory corruption vulnerability in nnn, published on 19 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
nnn is vulnerable to Out-of-Bound write vulnerability. Due to lack of validation of attacker-controlled length fields deserialized from a session file, a crafted session file can cause nnn to write data beyond the bounds of fixed-size global buffers when loaded with the -s option. An attacker who can place a malicious session file in the victim's nnn session directory can exploit this to corrupt adjacent global state.
Maintainer of this project was notified about this vulnerability. It might has been addressed, but the maintainer did not provide a vulnerable version range. Only version 5.2 was tested and confirmed as vulnerable.
Weakness: CWE-787
Which versions are affected by CVE-2026-65609?
How do I fix CVE-2026-65609?
No fix has been published for CVE-2026-65609 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-65609 being exploited?
There is no known exploitation of CVE-2026-65609 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-65609, GHSA-r4wp-c597-23pf, UBUNTU-CVE-2026-65609.