CVE-2026-41921 — Koha Stored XSS via Purchase Suggestion Handler
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (medium)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Koha Community Koha).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (cross-site scripting), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Koha Community | Koha | ≥ 26.05.0 and < 26.05.02≥ 25.11.0 and < 25.11.07≥ 25.05.0 and < 25.05.13 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 5.1 | CVSS 4.0 | Medium | — | — | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 5.1 | CVSS 4.0 | Medium | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
| 5.4 | CVSS 3.1 | Medium | 2.3 | 2.7 | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 5.4 | CVSS 3.1 | Medium | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N (score shown at the top: disclosure@vulncheck.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Monitor CSP violation reports and script payloads in reflected parameters.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · koha community/koha
- SSVC assessment updated
- Record published
- CVSS changed · 5.4
- Source status changed · → Awaiting Analysis
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-105106 Koha authenticated OS command injection in tools/scheduler.pl via the jobid parameter when deleting a scheduled task 1d
- High CVE-2026-105107 Koha SQL injection in reports/cat_issues_top.pl via the Criteria, Filter and Limit request parameters 1d
- Medium CVE-2026-72610 Koha Community Koha - Stored SQL Injection via Patron lang Field in Issue Slip Generation Aug 11, 2026
- High CVE-2026-72609 Koha Community Koha - SQL Injection via ORDER BY Direction in acqui/parcels.pl Aug 11, 2026
- High CVE-2026-72607 Koha Community Koha - Stored SQL Injection via agefield in Automatic Item Modifications by Age Aug 11, 2026
- Medium CVE-2026-72608 Koha Community Koha - Stored SQL Injection via Patron Card Layout image_name Aug 11, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-41921 is "Koha Stored XSS via Purchase Suggestion Handler", rated Medium. It affects Koha (Koha Community); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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