Author-level stored XSS via flawed image-attribute regex
Published Aug 28, 2026 · Updated Aug 28, 2026
Stored cross-site scripting in LiteSpeed Cache for WordPress 7.7 and earlier allows remote authenticated users to inject scripts via image attributes. The media optimizer applies a flawed regular expression when removing width and height attributes, allowing crafted img attributes to retain executable script. Author-level access and both Lazy Load Images and Add Missing Sizes are required, and the script runs when a logged-out visitor opens the post.
Summary
What happened
Stored cross-site scripting in LiteSpeed Cache for WordPress 7.7 and earlier allows remote authenticated users to inject scripts via image attributes. The media optimizer applies a flawed regular expression when removing width and height attributes, allowing crafted img attributes to retain executable script. Author-level access and both Lazy Load Images and Add Missing Sizes are required, and the script runs when a logged-out visitor opens the post.
The record
- CVE
- CVE-2026-3129
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Vendor
- LiteSpeed Technologies
- Product
- LiteSpeed Cache for WordPress
- Classifications
- CWE-79, T1059.007
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 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.
- Affected versionversion=0 <=7.7
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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