Quick answers
- Is CVE-2026-91944 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-91944 being exploited in the wild.
- How severe is CVE-2026-91944?
- Medium severity, with a CVSS score of 6.1, published 15 September 2026.
- Which products and versions are affected?
- crawl4ai crawl4ai < 0.9.3.
- Is there a fix for CVE-2026-91944?
- A patch was published on 2026: Version 0.9.3 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-91944 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-91944?
- Check whether anything you run is named in the advisory. 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 DOM-based XSS (CWE-79) in the Playground UI's forceHighlightElement() function (deploy/docker/static/playground/index.html, lines 972–988). The function retrieves textContent from an element containing stringified JSON response data and writes it back to innerHTML, causing the browser to re-parse and execute any embedded HTML/JavaScript. The attack vector leverages the fact that JSON.stringify() does not escape HTML special characters, and attacker-controlled content from crawled pages (e.g., page titles) survives this round-trip and executes as JavaScript. No Content Security Policy is enforced on the Playground UI endpoints, allowing inline script execution. The operator's API token is stored in sessionStorage (JavaScript-readable), enabling token theft via fetch exfiltration. The vulnerability affects crawl4ai versions before 0.9.3 and is patched in version 0.9.3 and later.
Affected products
- crawl4ai crawl4ai < 0.9.3
Timeline
- 2026-08-31: disclosed
- 2026-09-15: advisory
- 2026: patched: Version 0.9.3