High 8.7Published May 26, 2026

CVE-2026-43982Algernon: Path traversal file write via savein()

Updated under an hour ago (Oct 27, 2026, 5:23 AM ET)

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Every CVE for xyproto algernon

Exploited in the last 30 days

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: 8.7 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness (CWE): CWE-22
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: May 26, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

xyproto algernon xyproto:algernon (from the name)	before 1.17.6	CNA record

References

References

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

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.