Is CVE-2026-5217 actively exploited?

A proof-of-concept exploit is publicly available for CVE-2026-5217, but active exploitation has not been confirmed.

Can CVE-2026-5217 be exploited remotely?

Yes. CVE-2026-5217 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-5217?

CVE-2026-5217 has a CVSS score of 7.2 (HIGH).

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HIGHPOC

CVE-2026-5217

CWE-79Published: April 11, 2026· Updated: Apr 13, 2026

7.2

CVSS v3.1

Official Description

The Optimole – Optimize Images | Convert WebP & AVIF | CDN & Lazy Load | Image Optimization plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 4.2.2. This is due to insufficient input sanitization and output escaping on the user-supplied 's' parameter (srcset descriptor) in the unauthenticated /wp-json/optimole/v1/optimizations REST endpoint. The endpoint validates requests using an HMAC signature and timestamp, but these values are exposed directly in the frontend HTML making them accessible to any visitor. The plugin uses sanitize_text_field() on the descriptor value of rest.php, which strips HTML tags but does not escape double quotes. The poisoned descriptor is then stored via transients (backed by the WordPress options table) and later retrieved and injected verbatim into the srcset attribute of tag_replacer.php without proper escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts into pages that will execute whenever a user accesses the injected page.

NVD Source

Technical Analysis

CVE-2026-5217 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

A proof-of-concept (PoC) exploit exists for CVE-2026-5217. While not yet confirmed in active campaigns, the availability of PoC code increases exploitation risk substantially.

From a weakness classification perspective (CWE-79): Cross-site scripting (XSS) vulnerabilities allow attackers to inject malicious scripts into web pages viewed by other users.