Miniflux EUVD-2026-96901

Requires a valid authenticated account on the Miniflux instance (per-feed proxy_url is a logged-in user feature), and the attacker must be able to create or edit a feed and set its proxy_url to a loopback or internal host; the flaw specifically defeats the FETCHER_ALLOW_PRIVATE_NETWORKS safeguard for the proxy_url path. Limiting factors: exploitation is impossible for unauthenticated outsiders, impact is confined to internal port probing and proxy-style requests (low confidentiality disclosure, no write/RCE/DoS), and it affects only versions 2.3.0 through 2.3.3.

This is a moderate, authenticated SSRF (CWE-918) with convergent-but-modest signals rather than an urgent priority. The provided CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N, score 5.3) is internally consistent with the description: network-reachable, low complexity, no user interaction, but PR:L confirms an authenticated account is required, and impact is confined to low confidentiality (internal port probing and proxy-style requests) with no integrity or availability effect. No EPSS score was supplied, so exploitation probability cannot be quantified. The vulnerability is NOT in CISA KEV (no KEV signal in input), so there is no evidence of active exploitation. A detailed public technical writeup (hackmd) documents the private-network bypass, so proof-of-concept-level exploitation detail is publicly available even if no packaged exploit tool is confirmed. The net picture is a real but bounded issue: it requires an existing authenticated user, yields only low-impact internal reconnaissance/relay rather than code execution or data theft, and affects a niche self-hosted product - so it merits patching but does not rise to emergency priority. Note the authentication gate (PR:L) is the single most important limiting factor and is confirmed by the CVSS vector.

An authenticated Miniflux user (2.3.0-2.3.3) creates or edits a feed and sets its proxy_url to a loopback or internal address such as http://127.0.0.1:port or an internal service host. When Miniflux fetches the feed through that proxy, it bypasses the FETCHER_ALLOW_PRIVATE_NETWORKS restriction, letting the attacker probe internal ports and relay proxy-style requests to services otherwise unreachable from outside. A public technical writeup describing the bypass exists, lowering the effort to reproduce it.