CVE intelligence and bounded remediation

CVE-2025-50578 — Linuxserver Docker-Heimdall security vulnerability

Critical CVSS 9.8

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.

Severity
Critical
CVSS
9.8 (3.1)
Published
2025-07-30
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-20, CWE-74, CWE-601

Affected products

  • linuxserver / docker-heimdall / 2.6.3-ls307

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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