# CVE-2026-84829: Optimole Stored Cross-Site Scripting in image tag attributes

Source: https://junglewise.ai/threats/cve-2026-84829-optimole-stored-cross-site-scripting-in-image-tag-attributes  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-16. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-84829 · Severity: high · CVSS 8.8 · Published 2026-09-16

Optimole is a popular WordPress plugin that optimizes images for faster website loading. An improper escaping vulnerability in versions before 4.2.12 allows unauthenticated attackers to inject malicious code into image attributes, which is then stored and served to all site visitors. This can lead to credential theft, malware distribution, or defacement of the website.

Technologies: [Optimole](https://junglewise.ai/threats/technologies/optimole). Vendors: [Optimole](https://junglewise.ai/threats/vendors/optimole).

## Quick answers

**Is CVE-2026-84829 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-84829 being exploited in the wild.

**How severe is CVE-2026-84829?** High severity, with a CVSS score of 8.8, published 16 September 2026.

**Which products and versions are affected?** Optimole before 4.2.12.

**Is there a fix for CVE-2026-84829?** A patch was published on 2026-09-16: Fixed in version 4.2.12 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-84829 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-84829?** Check whether you run Optimole at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a Stored Cross-Site Scripting (XSS) flaw (CWE-79) in the Optimole WordPress plugin. The plugin fails to properly escape user-supplied values before using them in image tag attributes, specifically in the srcset descriptor parameter. Unauthenticated attackers can inject arbitrary HTML/JavaScript attributes through this parameter. Previous escaping added in version 4.2.3 did not account for the final context in which the value is used, so versions 4.2.3 through 4.2.11 remain vulnerable. The injected payload is stored in the database and rendered to all site visitors, making this a high-impact stored XSS. A patch is available in version 4.2.12.

## Affected products

- Optimole Optimole before 4.2.12

## Timeline

- 2026-09-14: disclosed
- 2026-09-16: patched: Fixed in version 4.2.12

## References

- [https://wpscan.com/vulnerability/c8489eb1-e767-4b19-a7c0-124eab843d9e/](https://wpscan.com/vulnerability/c8489eb1-e767-4b19-a7c0-124eab843d9e/)

## Related threats

- [Optimole broken access control in WordPress plugin](https://junglewise.ai/threats/cve-2026-102375-subscriber-broken-access-control-in-optimole-4-2-14-versions)
- [Optimole WordPress plugin unauthenticated XSS](https://junglewise.ai/threats/cve-2026-57673-optimole-wordpress-plugin-unauthenticated-xss)
- [Optimole WordPress Plugin CSRF in replace_file function](https://junglewise.ai/threats/cve-2026-11784-optimole-wordpress-plugin-csrf-in-replace-file-function)