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Fencer Vulns
medium 4.3

CVE-2025-46339 json

FreshRSS vulnerable to favicon cache poisoning via proxy

published 2025-06-04 17 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-16931

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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.

Patch / fix

  • freshrss freshrss 1.26.2

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
17 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FreshRSS/FreshRSS/security/advisories/GHSA-8f79-3q3w-43c4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Affected products

  • FreshRSS FreshRSS

Classification

Weakness
  • CWE-349 Acceptance of Extraneous Untrusted Data With Trusted Data

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.