CVE-2025-48865

CRITICAL EPSS 39.7%
Published May 30, 20251y ago · Modified Jun 17, 20262w ago
9.1 CVSS 3.1
Critical
Find Similar
Published May 30, 2025 1y ago
Last Modified Jun 17, 2026 2w ago

Description

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. Prior to version 1.6.6, Fabio allows clients to remove X-Forwarded headers (except X-Forwarded-For) due to a vulnerability in how it processes hop-by-hop headers. Fabio adds HTTP headers like X-Forwarded-Host and X-Forwarded-Port when routing requests to backend applications. Since the receiving application should trust these headers, allowing HTTP clients to remove or modify them creates potential security vulnerabilities. Some of these custom headers can be removed and, in certain cases, manipulated. The attack relies on the behavior that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been patched in version 1.6.6.

CVSS Details

Base Score
9.1
Exploitability
3.9
Impact
5.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
39.7% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 2

CWE-345
CWE-348

Affected Products 1

VendorProductVersionRange
fabiolbfabio* <1.6.6

References 3

  • github.com https://github.com/fabiolb/fabio/commit/fdaf1e966162e9dd3b347ffdd0647b39dc71a1a3
    Patch
  • github.com https://github.com/fabiolb/fabio/releases/tag/v1.6.6
    Release Notes
  • github.com https://github.com/fabiolb/fabio/security/advisories/GHSA-q7p4-7xjv-j3wf
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/fabiolb/fabio/commit/fdaf1e966162e9dd3b347ffdd0647b39dc71a1a3
    Patch