CVE-2026-21885: Miniflux Media Proxy SSRF via /proxy endpoint allows access to internal network resources

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-01-08 · updated 2026-06-17
Weakness: CWE-918

Description

Miniflux 2 is an open source feed reader. Prior to version 2.2.16, Miniflux's media proxy endpoint (`GET /proxy/{encodedDigest}/{encodedURL}`) can be abused to perform Server-Side Request Forgery (SSRF). An authenticated user can cause Miniflux to generate a signed proxy URL for attacker-chosen media URLs embedded in feed entry content, including internal addresses (e.g., localhost, private RFC1918 ranges, or link-local metadata endpoints). Requesting the resulting `/proxy/...` URL makes Miniflux fetch and return the internal response. Version 2.2.16 fixes the issue.

Affected products

miniflux: from 2.0.0 before 2.2.16 — fixed in 2.2.16

How to fix

Upgrade to a fixed version: miniflux 2.2.16. Check the vendor advisory for mitigations.

References

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