CVE-2026-65609
LowCVSS 2.4Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
nnn is vulnerable to an out-of-bounds 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. Only version 5.2 was tested and confirmed as vulnerable.
Risk Assessment
The risk is the possibility of corrupting global memory, which could lead to program crashes, unpredictable behavior, or potentially privilege escalation depending on the context.
Recommendation
It is recommended to update nnn to the latest available version if a fix has been released, or to avoid loading session files from untrusted sources.
Original NVD description (English source)
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.