miniflux up to 2.2.15 /proxy/ server-side request forgery

Summaryinfo

A vulnerability was found in miniflux up to 2.2.15 and classified as critical. Affected by this vulnerability is an unknown functionality of the file /proxy/. Executing a manipulation can lead to server-side request forgery. This vulnerability is registered as CVE-2026-21885. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in miniflux up to 2.2.15. This vulnerability affects an unknown code of the file /proxy/. The manipulation with an unknown input leads to a server-side request forgery vulnerability. The CWE definition for the vulnerability is CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-21885 since 01/05/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 282485 (Linux Distros Unpatched Vulnerability : CVE-2026-21885), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.2.16 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (282485). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• miniflux

Version

• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 2.2.7
• 2.2.8
• 2.2.9
• 2.2.10
• 2.2.11
• 2.2.12
• 2.2.13
• 2.2.14
• 2.2.15

CPE 2.3info

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CPE 2.2info

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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