CVE-2026-65610 Numeric Truncation Error in nnn
An attacker can trigger an out-of-bounds read and write in nnn by providing a long HOME path, potentially leading to code execution or crashes.
- 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-2026-65610?
CVE-2026-65610 is a low-severity 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 stores homelen variable as uchar_t, which can only represent values in the range 0-255. An attacker who can influence the victim's execution environment can provide an arbitrary HOME path with length that is truncated to 0. The expression (homelen - 1) is promoted to signed int and becomes -1 and producing an out-of-bounds read and an out-of-bounds write one byte before the path buffer.
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-197
Which versions are affected by CVE-2026-65610?
How do I fix CVE-2026-65610?
No fix has been published for CVE-2026-65610 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-65610 being exploited?
There is no known exploitation of CVE-2026-65610 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-65610, GHSA-2fq9-p2vj-rc2v, UBUNTU-CVE-2026-65610.