CVE-2026-3129 LiteSpeed Cache <= 7.7 - Authenticated (Author+) Stored Cross-Site Scripting via img Tag Attributes
Authenticated attackers can inject arbitrary scripts via img tags in LiteSpeed Cache when specific lazy loading features are enabled.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-3129?
CVE-2026-3129 is a medium-severity cross-site scripting vulnerability in litespeedtech LiteSpeed Cache, published on 28 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-3129?
How do I fix CVE-2026-3129?
No fix has been published for CVE-2026-3129 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-3129 being exploited?
There is no known exploitation of CVE-2026-3129 in the wild and no public exploit code.
Sources
Also known as GHSA-g9h6-rmm3-xq5v.