CVE-2026-66917Public exploitNetwork attack vector

Stored XSS via unescaped image titles

Published Aug 22, 2026 · Updated Aug 22, 2026

Stored XSS in JoomGallery 4.0.0 through 4.3.0 allows remote authenticated users to execute JavaScript in gallery visitors' browsers. The frontend image template writes an image title into an HTML alt attribute without encoding quotes, allowing stored title data to inject event handlers. The attack requires an authenticated account with image-editing privileges; viewing a tainted gallery image triggers execution in the visitor's site origin.

CVSS severity8.6
High
EPSS probability0.47%
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 JoomGallery 4.0.0 through 4.3.0 allows remote authenticated users to execute JavaScript in gallery visitors' browsers. The frontend image template writes an image title into an HTML alt attribute without encoding quotes, allowing stored title data to inject event handlers. The attack requires an authenticated account with image-editing privileges; viewing a tainted gallery image triggers execution in the visitor's site origin.

The record

CVE
CVE-2026-66917
Published
Aug 22, 2026
Updated
Aug 22, 2026
Vendor
JoomGallery friends
Product
JoomGallery
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 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=4.0.0-4.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

JoomGallery friends · JoomGalleryversion=4.0.0-4.3.0

Published CVSS scores

8.6Joomla! ProjectCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

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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