{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-121550","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-03T14:46:14.575Z","datePublished":"2026-11-03T15:17:09.442Z","dateUpdated":"2026-11-03T15:17:09.442Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-03T15:17:09.442Z"},"datePublic":"2026-10-31T00:00:00.000Z","title":"nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Link Resolution Before File Access ('Link Following')","cweId":"CWE-59","type":"CWE"}]}],"affected":[{"vendor":"jarun","product":"nnn","defaultStatus":"unaffected","versions":[{"version":"0","lessThanOrEqual":"5.3","versionType":"custom","status":"affected"}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"ACTIVE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":1,"baseSeverity":"LOW"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N","attackVector":"LOCAL","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":3.3,"baseSeverity":"LOW"}}],"references":[{"url":"https://github.com/jarun/nnn/issues/2188","tags":["issue-tracking"],"name":"GitHub Issue #2188"},{"url":"https://github.com/jarun/nnn","tags":["product"]},{"url":"https://github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff","tags":["patch"],"name":"Fix commit"},{"url":"https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L10635","tags":["technical-description"]},{"url":"https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L7433","tags":["technical-description"]},{"name":"VulnCheck Advisory: nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/nnn-through-5.3-symlink-following-write-via-nnn-fifo-handling"}],"credits":[{"lang":"en","value":"George Chen","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}}}}