XSS in Webrecorder Wabac.js
CVE-2025-58765
wabac.js provides a full web archive replay system, or 'wayback machine', using Service Workers. A Reflected Cross-Site Scripting (XSS) vulnerability exists in the 404 error handling logic of wabac.js v2.23.10 and below. The parameter `requestURL` (derived from the original request target) is directly embedded into an inline `<script>` block without sanitization or escaping. This allows an attacker to craft a malicious URL that executes arbitrary JavaScript in the victim’s browser. The scope may be limited by CORS policies, depending on the situation in which wabac.js is used. The vulnerability is fixed in wabac.js v2.23.11.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (14.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L.
Affected products
- Webrecorder Wabac.js — versions < 2.23.11
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-58765?
- CVE-2025-58765 is a high-severity vulnerability in Webrecorder Wabac.js, classified under Cross-site Scripting. CVSS score: 7.1/10. Published 2025-09-09.
- How severe is CVE-2025-58765?
- High severity. CVSS v3 base score is 7.1 out of 10.
- Is CVE-2025-58765 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.