XSS in Litespeedtech Litespeed Cache

CVE-2026-109215

The LiteSpeed Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'bbp_reply_content' parameter in all versions up to, and including, 7.9.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires that an administrator has enabled Viewport Images (VPI) and configured a VPI filename that matches an image the attacker can embed in user-generated content — such as a bbPress topic where Subscriber-level Participants are permitted to post replies containing raw img tags.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (26.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-109215?
CVE-2026-109215 is a medium-severity vulnerability in Litespeedtech Litespeed Cache, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-10-29.
How severe is CVE-2026-109215?
Medium severity. CVSS v3 base score is 6.4 out of 10.