CVE-2026-91944 PUBLISHED

crawl4ai before 0.9.3 DOM-based XSS via Playground UI

Assigner: VulnCheck
Reserved: 15.09.2026 Published: 15.09.2026 Updated: 15.09.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CVSS Score: 5.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	Low
Attack Complexity	Low	Integrity	Low	Integrity	Low
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	None
User Interaction	Active

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS Score: 6.1

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	unclecode
Product	crawl4ai
Versions	Default: unaffected affected from 0 to 0.9.3 (excl.) Version 0.9.3 is unaffected

Credits

e1codes reporter

References

Problem Types

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE