Path Traversal in Koodo-Reader
CVE-2026-121544
Koodo Reader through 2.4.6 contains a path traversal vulnerability in the self-hosted HTTP server's OPDS handlers that allows authenticated attackers to read files outside the upload directory. Attackers can upload a crafted books.db with a cover value containing ../ sequences, then request /opds/cover/{key} to read files accessible to the server process.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/koodo-reader/koodo-reader/issues/1654 (issue-tracking)
- github.com/koodo-reader/koodo-reader (product)
- github.com/koodo-reader/koodo-reader/commit/cbc79a1ab5cbbd61c8252d6ab3cc6dbb694… (patch)
- github.com/koodo-reader/koodo-reader/blob/v2.4.6/httpserver/opds.go (technical-description)
- github.com/koodo-reader/koodo-reader/blob/v2.4.6/httpserver/opds.go (technical-description)
- github.com/koodo-reader/koodo-reader/compare/205539043b0a2afd9fd8bf99ef8434bd18… (technical-description)
- www.vulncheck.com/advisories/koodo-reader-through-2.4.6-path-traversal-via-opds… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-121544?
- CVE-2026-121544 is a medium-severity vulnerability in Koodo-Reader, classified under Path Traversal. CVSS score: 4.9/10. Published 2026-11-03.
- How severe is CVE-2026-121544?
- Medium severity. CVSS v3 base score is 4.9 out of 10.