CVE-2025-50578 — CRITICAL (9.8)

Vulnerability 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.

CVSS Score

9.8

CRITICAL

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Linuxserver	Docker-Heimdall	2.6.3-ls307

Related Weaknesses (CWE)

CWE-20 CWE-601 CWE-74

References

https://github.com/linuxserver/HeimdallProduct
https://github.com/linuxserver/Heimdall/issues/1451ExploitIssue Tracking
https://medium.com/@juanfelipeoz.rar/cve-2025-50578-exploiting-host-header-injecExploitThird Party Advisory

FAQ

What is CVE-2025-50578?

CVE-2025-50578 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 manipul...

How severe is CVE-2025-50578?

CVE-2025-50578 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2025-50578?

Check the references section above for vendor advisories and patch information. Affected products include: Linuxserver Docker-Heimdall.