CVE-2026-78438
W3 Total Cache <= 2.10.5 - Unauthenticated Stored Cross-Site Scripting via LazyLoad Background Mutator
CVE-2026-78438 is a high vulnerability (CVSS 7.2) in Boldgrid W3 Total Cache, published September 5, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.50%, the 43rd percentile. No source names a fixed version.
- Severity
- 7.2 HighCVSS 3.1, CVE List
- Exploit chance
- 0.50%EPSS, 43rd percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the "Lazy Load Images" feature with "Process background images" to be enabled, and the malicious comment to be approved by a moderator before execution is triggered.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
Affected products
What each source reports
CVE List Score used
W3 Total Cache <= 2.10.5 - Unauthenticated Stored Cross-Site Scripting via LazyLoad Background Mutator
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the "Lazy Load Images" feature with "Process background images" to be enabled, and the malicious comment to be approved by a moderator before execution is triggered.
- Record
CVE-2026-78438- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-71882
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the "Lazy Load Images" feature with "Process background images" to be enabled, and the malicious comment to be approved by a moderator before execution is triggered.
- Record
EUVD-2026-71882- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6p3q-4gcg-xv4v
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment...
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the "Lazy Load Images" feature with "Process background images" to be enabled, and the malicious comment to be approved by a moderator before execution is triggered.
- Record
GHSA-6p3q-4gcg-xv4v- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
The W3 Total Cache plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content via LazyLoad Background Mutator in all versions up to, and including, 2.10.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the "Lazy Load Images" feature with "Process background images" to be enabled, and the malicious comment to be approved by a moderator before execution is triggered.
- Record
CVE-2026-78438- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
wordfence.com/threat-intel/vulnerabilities/id/5580ad05-af50-4899-9cbf-39ad8000eb6a?source=cve
plugins.trac.wordpress.org/browser/w3-total-cache/tags/2.10.5/UserExperience_LazyLoad_Mutator.php
nvd.nist.gov/vuln/detail/CVE-2026-78438
github.com/advisories/GHSA-6p3q-4gcg-xv4v