{"id":"CVE-2026-121550","title":"nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling","summary":"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 pred…","severity":"low","cvss":3.3,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-59"],"vendor":"jarun","product":"nnn","affected":["nnn <= 5.3"],"published":"2026-11-03","updated":"2026-11-03","sourceUpdated":"2026-11-03T15:17:09.442Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-121550","references":[{"url":"https://github.com/jarun/nnn/issues/2188","label":"GitHub Issue #2188"},{"url":"https://github.com/jarun/nnn"},{"url":"https://github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff","label":"Fix commit"},{"url":"https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L10635"},{"url":"https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L7433"},{"url":"https://www.vulncheck.com/advisories/nnn-through-5.3-symlink-following-write-via-nnn-fifo-handling","label":"VulnCheck Advisory: nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling"}],"tags":["cve.org"],"epss":0.00116,"epssPercentile":0.01619,"ingestedAt":"2026-11-05T19:30:42.975Z","slug":"CVE-2026-121550","body":"## Overview\n\nnnn 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.\n\n## Affected\n\n- `nnn <= 5.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":18,"depthScoreParts":{"impact":18.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}