What’s Vulnerable › Vulnerabilities

CVE-2026-3129: LiteSpeed Cache <= 7.7 - Authenticated (Author+) Stored Cross-Site Scripting via img Tag Attributes

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-28 · updated 2026-08-29
• Weakness: CWE-79

Description

The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via crafted `<img>` tag attributes in all versions up to, and including, 7.7. This is due to a flawed regular expression that is used to strip `width` and `height` attributes from images when the "Lazy Load Images" and "Add Missing Sizes" features are enabled. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that execute whenever a user accesses an injected page.

Affected products

• LiteSpeed Technologies LiteSpeed Cache: through 7.7

References

• https://blog.litespeedtech.com/2026/08/27/security-update-for-lscwp-cve-2026-3129/
• https://plugins.trac.wordpress.org/browser/litespeed-cache/trunk/src/media.cls.php#L761
• https://plugins.trac.wordpress.org/changeset/3473912/
• https://www.wordfence.com/threat-intel/vulnerabilities/id/c107674d-173f-49cf-b329-e7bffaee841d?source=cve

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