CVE-2026-26377Public exploitNetwork attack vector

Session compromise via unsanitized stored News content

Published Mar 5, 2026 · Updated Mar 5, 2026

Stored cross-site scripting in Koha 25.11 and earlier allows remote authenticated users to execute script through crafted News content. The News editor saves script-bearing content without neutralization, and the main page renders that stored content in other users’ browsers. An account permitted to add News is required; viewing the affected page triggers the payload, enabling data theft or impersonation in the viewer’s session.

CVSS severity5.4
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in Koha 25.11 and earlier allows remote authenticated users to execute script through crafted News content. The News editor saves script-bearing content without neutralization, and the main page renders that stored content in other users’ browsers. An account permitted to add News is required; viewing the affected page triggers the payload, enabling data theft or impersonation in the viewer’s session.

The record

CVE
CVE-2026-26377
Published
Mar 5, 2026
Updated
Mar 5, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A: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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

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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