Description
nnn through 5.3 contains an insecure file handling vulnerability that allows local attackers to redirect writes because main() accepts an existing NNN_FIFO path without verifying it is a FIFO. Attackers can pre-create the documented predictable /tmp/nnn.fifo path as a symlink or readable regular file, causing victim-writable files to be overwritten or leaking the victim's browsed paths.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| jarun | nnn | ≤ 5.3 | — |
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
- GitHub Issue #2188 issue-tracking
- https://github.com/jarun/nnn product
- Fix commit patch
- https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L10635 technical-description
- https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L7433 technical-description
- VulnCheck Advisory: nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling third-party-advisory