SSRF in Koha
CVE-2026-26379
Koha versions up to 25.11 contain a Server-Side Request Forgery (SSRF) vulnerability via the Z39.50/SRU server configuration. This allows authenticated attackers to perform internal network scanning and identify running services by analyzing server response times.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (15.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 15.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.002 · change: -0.001
Affected products
Weakness classification (CWE)
References
- github.com/Koha-Community/Koha (Product)
- g03m0n.github.io/ (Third Party Advisory)
- g03m0n.github.io/posts/cve-2026-26379/ (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-26379?
- CVE-2026-26379 is a medium-severity vulnerability in Koha, classified under Server-Side Request Forgery (SSRF). CVSS score: 6.5/10. Published 2026-06-03.
- How severe is CVE-2026-26379?
- Medium severity. CVSS v3 base score is 6.5 out of 10.