CVE-2026-3129: medium-severity vulnerability in litespeedtech LiteSpeed Cache
LiteSpeed Cache <= 7.7 - Authenticated (Author+) Stored Cross-Site Scripting via img Tag Attributes
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.4epss 0.3%
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
Affected products
litespeedtech · LiteSpeed CacheRelated CVEs — litespeedtech LiteSpeed Cache
In the same product, most dangerous first.
CVE-2023-4372MEDIUMLiteSpeed Cache <= 5.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via ShortcodeEPSS 19.5%CVE-2026-18978HIGHLiteSpeed Cache <= 7.8.1 - Unauthenticated Stored Cross-Site Scripting via Comment ContentEPSS 0.4%CVE-2026-76579MEDIUMLiteSpeed Cache <= 7.9 - Reflected Cross-Site Scripting via ESI 'esi' ParameterEPSS 0.4%CVE-2025-12450MEDIUMLiteSpeed Cache <= 7.5.0.1 - Reflected Cross-Site ScriptingEPSS 0.4%CVE-2026-3375HIGHLiteSpeed Cache <= 7.7 - Unauthenticated Stored Cross-Site Scripting via QUIC.cloud CCSS/UCSS REST API EndpointsEPSS 0.4%CVE-2026-116763MEDIUMLiteSpeed Cache <= 7.9.1 - Unauthenticated Stored Cross-Site Scripting via HTML Minifier Predictable Placeholder (md5(REQUEST_TIME) + two-pass str_replace)EPSS 0.3%
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#L761https://plugins.trac.wordpress.org/changeset/3473912/https://www.wordfence.com/threat-intel/vulnerabilities/id/c107674d-173f-49cf-b329-e7bffaee841d?source=cve