nnn through 5.3 Symlink-Following Write via NNN_FIFO Handling
Summary
| CVE | CVE-2026-121550 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-03 16:17:26 UTC |
| Updated | 2026-11-03 16:30:17 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 1 LOW from [email protected]
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
Problem Types: CWE-59 | CWE-59 Improper Link Resolution Before File Access ('Link Following')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 1 | LOW | 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/C... |
| 4.0 | CNA | CVSS | 1 | LOW | 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 |
| 3.1 | [email protected] | Primary | 3.3 | LOW | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N |
| 3.1 | CNA | CVSS | 3.3 | LOW | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
PresentPrivileges Required
LowUser Interaction
ActiveConfidentiality
LowIntegrity
LowAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
LowUser Interaction
RequiredScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/jarun/nnn/commit/04715921aece0257fef7a8558c0783493d98efff | [email protected] | github.com | |
| github.com/jarun/nnn | [email protected] | github.com | |
| github.com/jarun/nnn/blob/v5.3/src/nnn.c | [email protected] | github.com | |
| github.com/jarun/nnn/issues/2188 | [email protected] | github.com | |
| www.vulncheck.com/advisories/nnn-through-5.3-symlink-following-write-via-nnn-fi... | [email protected] | www.vulncheck.com | |
| github.com/jarun/nnn/blob/v5.3/src/nnn.c | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: George Chen (en)
There are currently no legacy QID mappings associated with this CVE.