CVE-2025-46339: FreshRSS vulnerable to favicon cache poisoning via proxy

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-06-04 · updated 2026-06-17
Weakness: CWE-349

Description

FreshRSS is a self-hosted RSS feed aggregator. Prior to version 1.26.2, it's possible to poison feed favicons by adding a given URL as a feed with the proxy set to an attacker-controlled one and disabled SSL verifying. The favicon hash is computed by hashing the feed URL and the salt, whilst not including the following variables: proxy address, proxy protocol, and whether SSL should be verified. Therefore it's possible to poison a favicon of a given feed by simply intercepting the response of the feed, and changing the website URL to one where a threat actor controls the feed favicon. Feed favicons can be replaced for all users by anyone. Version 1.26.2 fixes the issue.

Affected products

FreshRSS: before 1.26.2 — fixed in 1.26.2

How to fix

Upgrade to a fixed version: FreshRSS 1.26.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2025-46339 or the next vulnerability affects your stack