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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| nnn | nnn | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | nnn | No fix yet | — |
| Debian 13 | nnn | No fix yet | — |
| Debian 12 | nnn | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | nnn | No fix yet | — |
| Ubuntu 26.04 LTS | nnn | No fix yet | — |
| Ubuntu 24.04 LTS | nnn | No fix yet | — |
| Ubuntu 22.04 LTS | nnn | No fix yet | — |
| Ubuntu 20.04 LTS | nnn | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | nnn | No fix yet | — |
References
- https://cert.pl/en/posts/2026/08/CVE-2026-65609 third-party-advisory