XSS in Koha Community
CVE-2026-41921
Koha before 26.05.02, 25.11.07, and 25.05.13 contains a stored cross-site scripting vulnerability in the purchase suggestion handler that allows authenticated staff users to inject malicious scripts by submitting unsanitized input through the suggestion save operation. Attackers can supply crafted HTML or script content in fields such as title, author, isbn, publishercode, place, collectiontitle, itemtype, and note, which are stored without sanitization and later rendered in the suggestion list template, causing injected scripts to execute in the browser of any staff user who views the suggestions.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- v25.05.13 Release Notes (release-notes)
- v25.11.07 Release Notes (release-notes)
- v26.05.02 Release Notes (release-notes)
- www.vulncheck.com/advisories/koha-stored-xss-via-purchase-suggestion-handler (third-party-advisory)
Frequently asked questions
- What is CVE-2026-41921?
- CVE-2026-41921 is a medium-severity vulnerability in Koha Community, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-08-18.
- How severe is CVE-2026-41921?
- Medium severity. CVSS v3 base score is 5.4 out of 10.