CVE-2026-121550: jarun nnn · Link Following
Affects jarun nnnSource CVE Database V5
Not known to be exploited · CVSS 1.0 Low.
Data as of 3 Nov 2026, 15:43 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 1.0 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 3.3 |
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 3 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| jarunnnn | Affected
| Fixed in– |
AI-suggested
Since the vulnerability requires local access and predictable FIFO path manipulation, mitigation includes ensuring that the /tmp/nnn.fifo path is not pre-created by untrusted users and verifying the FIFO file type before use. Users should monitor vendor advisories for any official fixes or updates addressing this issue.
Description
CVE-2026-121550 is a low-severity vulnerability in nnn through version 5.3 involving improper link resolution before file access. The main() function accepts a path to NNN_FIFO without verifying that it is a FIFO special file. This allows local attackers to pre-create the predictable /tmp/nnn.fifo path as a symlink or regular file, potentially causing victim-writable files to be overwritten or exposing the victim's browsed paths.
References
- github.com/jarun/nnn/issues/2188 (opens in a new tab)
- github.com/jarun/nnn (opens in a new tab)
- github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff (opens in a new tab)
- github.com/jarun/nnn/blob/v5.3/src/nnn.c (opens in a new tab)
- github.com/jarun/nnn/blob/v5.3/src/nnn.c (opens in a new tab)
- vulncheck.com/advisories/nnn-through-5.3-symlink-following-write-via-nnn-fifo-handling (opens in a new tab)