{"id":"CVE-2026-121550","aliases":["DEBIAN-CVE-2026-121550","EUVD-2026-115895","GHSA-96gh-683j-p43h","UBUNTU-CVE-2026-121550"],"status":"published","title":"nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling","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.","severity":{"version":"4.0","score":1,"vector":"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","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00116,"percentile":0.01625,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-59"],"published":"2026-11-03T15:17:09Z","modified":"2026-11-06T19:00:06Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.7-1","4.8-1","4.9-1","5.0-1","5.1-1","5.2-1","5.3-1"]},{"source":"osv","ecosystem":"Debian:13","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.0-1","5.1-1","5.2-1","5.3-1"]},{"source":"osv","ecosystem":"Debian:14","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.0-1","5.1-1","5.2-1","5.3-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3-2","1.5-1","1.6-1","1.7-1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.6-1","2.7-1","2.8-1","2.8.1-1","2.9-1","3.0-1","3.0-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.5-1","4.3-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.8-1","4.9-1","4.9-1build1","4.9-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.1-1","5.2-1","5.3-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"nnn","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.0-1","5.1-1"]}],"products":[{"vendor":"jarun","product":"nnn"}],"references":[{"url":"https://github.com/jarun/nnn/issues/2188","tags":["issue-tracking","report"]},{"url":"https://github.com/jarun/nnn","tags":["product","package","report"]},{"url":"https://github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff","tags":["patch","fix","report"]},{"url":"https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L10635","tags":["technical-description","article","report"]},{"url":"https://github.com/jarun/nnn/blob/v5.3/src/nnn.c#L7433","tags":["technical-description","article","report"]},{"url":"https://www.vulncheck.com/advisories/nnn-through-5.3-symlink-following-write-via-nnn-fifo-handling","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121550","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-96gh-683j-p43h"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121550.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-121550","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-121550","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-121550","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-121550","title":"nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling","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.","status":"published","published":"2026-11-03T15:17:09.442Z","modified":"2026-11-09T15:09:36.936Z","cvss":[{"version":"4.0","score":1,"vector":"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","level":"low","assessor":"cna"},{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"low","assessor":"cna"}],"cwes":["CWE-59"],"updated_at":"2026-11-09T16:33:53.922525Z"}],"euvd":[{"id":"EUVD-2026-115895","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.","status":"published","published":"2026-11-03T15:17:09Z","modified":"2026-11-09T15:09:36Z","cvss":[{"version":"4.0","score":1,"vector":"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","level":"low"}],"updated_at":"2026-11-09T16:17:22.482171Z"}],"ghsa":[{"id":"GHSA-96gh-683j-p43h","title":"nnn through 5.3 contains an insecure file handling vulnerability that allows local attackers to...","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.","status":"published","published":"2026-11-03T18:31:04Z","modified":"2026-11-03T18:31:05Z","cvss":[{"version":"4.0","score":1,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low"},{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"low"}],"cwes":["CWE-59"],"updated_at":"2026-11-03T19:01:31.965978Z"}],"nvd":[{"id":"CVE-2026-121550","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.","status":"published","published":"2026-11-03T16:17:26.897Z","modified":"2026-11-09T15:17:11.947Z","cvss":[{"version":"4.0","score":1,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low","assessor":"secondary"},{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"low","assessor":"secondary"}],"cwes":["CWE-59"],"updated_at":"2026-11-09T18:15:13.699929Z"}],"osv":[{"id":"CVE-2026-121550","title":"nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling","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.","status":"published","published":"2026-11-03T15:17:09.442Z","modified":"2026-11-11T07:23:24.386006523Z","cvss":[{"version":"4.0","score":1,"vector":"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","level":"low"}],"cwes":["CWE-59"],"updated_at":"2026-11-10T02:45:42.584685Z"},{"id":"DEBIAN-CVE-2026-121550","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.","status":"published","published":"2026-11-03T16:17:26.897Z","modified":"2026-11-10T10:00:24.175401409Z","cvss":[{"version":"4.0","score":1,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low"}],"updated_at":"2026-11-10T10:26:30.347596Z"},{"id":"UBUNTU-CVE-2026-121550","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.","status":"published","published":"2026-11-03T16:17:00Z","modified":"2026-11-05T11:46:31.948215201Z","cvss":[{"version":"3.1","score":3.3,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N","level":"low"},{"version":"4.0","score":1,"vector":"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","level":"low"}],"updated_at":"2026-11-05T13:30:15.321876Z"}]}}