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CVE-2026-91204

MEDIUM 6.1

Published 2026-09-28 · Last modified 2026-09-30

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in Apache Roller 6.1.5 allows an anonymous remote attacker to store a comment containing a javascript: URI link that survives HTML comment formatting and can execute script in the browser of a visitor who clicks it. This affects only sites that enable HTML in comments (users.comments.htmlenabled=true) together with the HTMLSubset comment formatter; comment moderation, where enabled, delays publication. Users are recommended to upgrade to Apache Roller 6.1.6 or later, which restricts restored links to http, https and mailto URIs.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.4%chance of exploitation in 30 days · 32nd percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

6.1CVSS 3.1 · MEDIUM

  • ConfidentialityLow
  • IntegrityLow
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ⚠User interaction: A user must take an action (click / open a file)
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-91204/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-91204/poc.json

Affected

Vendors Apache Software Foundation

Products Apache Roller

Weakness (CWE)

  • CWE-79: : Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

All CVSS metrics

  • MEDIUM 6.1 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
  • MEDIUM 6.1 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Sources: NVD · CVE.org · EPSS