CVE-2026-65697CWE-79

Fathom Lite 1.3.1 Stored XSS via /collect Endpoint

Medium · published July 23, 2026

CVSS v4.0
5.1
EPSS
0%
Percentile
18.6
In the wild
Unconfirmed
What it is

Fathom Lite through 1.3.1 contains a stored cross-site scripting vulnerability in the analytics collection endpoint that allows unauthenticated attackers to inject a javascript: URI into the Top Pages dashboard by supplying a crafted hostname and pathname to the unauthenticated /collect endpoint. The parseHostname and parsePathname functions perform no URI scheme validation, allowing a javascript: hostname combined with a newline-prefixed pathname to be stored and later rendered as an anchor href in the authenticated dashboard without sanitization, enabling session hijacking and full account takeover when an operator clicks the poisoned entry.

The record
Technical detail
CVSS v4.0
5.1 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
EPSS
0.00273 · 18.6th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-07-23T16:29Z
EPSS history
Timeline
  • 23 JUL 16:29Z
    Fathom Lite 1.3.1 Stored XSS via /collect Endpoint
    cvelistv5