CVE-2025-50578

critical

Description

LinuxServer.io heimdall 2.6.3-ls307 contains a vulnerability in how it handles user-supplied HTTP headers, specifically `X-Forwarded-Host` and `Referer`. An unauthenticated remote attacker can manipulate these headers to perform Host Header Injection and Open Redirect attacks. This allows the loading of external resources from attacker-controlled domains and unintended redirection of users, potentially enabling phishing, UI redress, and session theft. The vulnerability exists due to insufficient validation and trust of untrusted input, affecting the integrity and trustworthiness of the application.

References

https://medium.com/@juanfelipeoz.rar/cve-2025-50578-exploiting-host-header-injection-open-redirect-in-heimdall-application-733afceff2ea

https://github.com/linuxserver/Heimdall/issues/1451

https://github.com/linuxserver/Heimdall

Details

Source: Mitre, NVD

Published: 2025-07-30

Updated: 2025-07-31

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00054