VulnerabilityDeferred

CVE-2026-43982

This vulnerability is fixed in 1.17.6.

HIGH 8.7EPSS 0.34%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Algernon is a small self-contained pure-Go web server. Prior to 1.17.6, uploadedFileSaveIn() in lua/upload/upload.go uses filepath.Join() with the caller-supplied directory but performs no boundary check after joining. A directory of ../../../tmp resolves cleanly to /tmp, outside the web root. This vulnerability is fixed in 1.17.6.

CVSS 4.0: 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/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/M
EPSS: 0.34% probability · 28th percentile
CISA KEV: Not listed
Weakness: CWE-22
Source: security-advisories@github.com

References

https://github.com/xyproto/algernon/issues/172
https://github.com/xyproto/algernon/security/advisories/GHSA-2j2c-pv62-mmcp

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.