CVE-2026-65697

MEDIUM

Fathom Lite 1.3.1 Stored XSS via /collect Endpoint

Title source: cna
STIX 2.1

Description

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.

References (2)

Core 2
Core References
Exploit technical-description exploit
Researcher Disclosure
https://github.com/geo-chen/oss/blob/main/fathom.md

Scores

CVSS v3 6.1
EPSS 0.0016
EPSS Percentile 5.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-79
Status published
Products (1)
usefathom/fathom < 1.3.1
Published Jul 23, 2026
Tracked Since Jul 23, 2026