Optimole <= 4.2.2 - Unauthenticated Stored Cross-Site Scripting via Srcset Descriptor Parameter
Summary
| CVE | CVE-2026-5217 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-11 02:16:02 UTC |
| Updated | 2026-04-11 02:16:02 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.2 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
| 3.1 | CNA | DECLARED | 7.2 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
LowIntegrity
LowAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Optimole | Optimole Optimize Images In Real Time | affected 4.2.2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.wordfence.com/threat-intel/vulnerabilities/id/50417068-339a-4ae5-9c90-8f08f... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/optimole-wp/tags/4.2.1/inc/rest.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/optimole-wp/trunk/inc/rest.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/optimole-wp/trunk/inc/rest.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/optimole-wp/tags/4.2.1/inc/rest.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/optimole-wp/trunk/inc/tag_replacer.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/optimole-wp/tags/4.2.1/inc/tag_replacer.php | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Quốc Huy (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-03-31T11:42:57.000Z | Vendor Notified |
| CNA | 2026-04-10T11:56:50.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.