What is CVE-2026-91944?

CVE-2026-91944 is a medium-severity vulnerability in Unclecode Crawl4ai, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-09-15.

How severe is CVE-2026-91944?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Unclecode Crawl4ai

CVE-2026-91944

crawl4ai versions before 0.9.3 contain a DOM-based cross-site scripting vulnerability in the Playground UI where the forceHighlightElement() function assigns textContent back to innerHTML, re-parsing JSON responses as HTML. Attackers can inject malicious scripts through crawled page content like the page title to steal the operator's API token from sessionStorage and gain full server control.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Unclecode Crawl4ai

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-91944?: CVE-2026-91944 is a medium-severity vulnerability in Unclecode Crawl4ai, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-09-15.
How severe is CVE-2026-91944?: Medium severity. CVSS v3 base score is 6.1 out of 10.