Vulnerability in Jarun Nnn
CVE-2026-121550
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.3 (Low). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/jarun/nnn/issues/2188 (issue-tracking)
- github.com/jarun/nnn (product)
- github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff (patch)
- github.com/jarun/nnn/blob/v5.3/src/nnn.c (technical-description)
- github.com/jarun/nnn/blob/v5.3/src/nnn.c (technical-description)
- www.vulncheck.com/advisories/nnn-through-5.3-symlink-following-write-via-nnn-fi… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121550?
- CVE-2026-121550 is a low-severity vulnerability in Jarun Nnn, classified under Improper Link Resolution Before File Access. CVSS score: 3.3/10. Published 2026-11-03.
- How severe is CVE-2026-121550?
- Low severity. CVSS v3 base score is 3.3 out of 10.