CVE-2026-41921Network attack vector

Staff-browser script execution via suggestion fields

Published Aug 18, 2026 · Updated Aug 18, 2026

Stored XSS in Koha before 26.05.02, 25.11.07, and 25.05.13 allows remote authenticated users to execute script in staff browsers. The purchase suggestion save path accepts HTML or script in fields such as title, author, isbn, publishercode, place, collectiontitle, itemtype, and note, and the suggestion list template later renders those stored values into staff pages. Exploitation requires staff-level access to submit a suggestion and another staff user to open the affected suggestions view; impact is limited to browser-context actions and data exposure available to that viewer.

CVSS severity5.4
Medium
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Koha before 26.05.02, 25.11.07, and 25.05.13 allows remote authenticated users to execute script in staff browsers. The purchase suggestion save path accepts HTML or script in fields such as title, author, isbn, publishercode, place, collectiontitle, itemtype, and note, and the suggestion list template later renders those stored values into staff pages. Exploitation requires staff-level access to submit a suggestion and another staff user to open the affected suggestions view; impact is limited to browser-context actions and data exposure available to that viewer.

The record

CVE
CVE-2026-41921
Published
Aug 18, 2026
Updated
Aug 18, 2026
Vendor
Koha Community
Product
Koha
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=25.05.0 <25.05.13
  2. Affected versionversion=25.11.0 <25.11.07
  3. Affected versionversion=26.05.0 <26.05.02

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Koha Community · Kohaversion=25.05.0 <25.05.13; version=25.11.0 <25.11.07; version=26.05.0 <26.05.02

Published CVSS scores

5.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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