CVE case study

CVE-2026-66591: Contributor Cross-Site Scripting in Media Library Assistant

A contributor-level cross-site scripting flaw in the Media Library Assistant plugin through 3.39 let saved input execute in a privileged browser context. Version 3.40 encodes the affected output.

Weakness
Cross-Site Scripting (XSS)
Affected
Media Library Assistant 3.39 and earlier
Remediation state
Upgrade to Media Library Assistant 3.40 or later
Advisory published
18 Aug 2026

Why it matters

Media Library Assistant extends the WordPress media library. Through version 3.39, a contributor could store input that was later rendered without output encoding, so it executed as script in a privileged browser context.

The public record scores the issue Medium at 6.5 and notes it requires a privileged user to view the affected page. Version 3.40 encodes the output.

References

Further reading

Evidence connected to this article.

Back to article start