GHSA-q7p4-7xjv-j3wf · Severity: critical · Ecosystem: go — Fabio allows HTTP clients to manipulate custom headers it adds
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.
Conclusion & alert: CVE-2025-48865 is rated High Exploit Risk (64.7/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.17%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
| EDB-ID | Source | Kind | Published | Link |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-03-26 | 0.06% | 0.17% | +0.11% |
| 2 | 2026-02-13 | 0.01% | 0.06% | +0.04% |
| 3 | 2025-05-30 | — | 0.01% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.1 | 3.1 | CRITICAL |
|
3.9 | 5.2 | [email protected] |
| 9.1 | 3.1 | CRITICAL |
|
3.9 | 5.2 | [email protected] |
GHSA-q7p4-7xjv-j3wf · Severity: critical · Ecosystem: go — Fabio allows HTTP clients to manipulate custom headers it adds
| URL | Tags |
|---|---|
| https://github.com/fabiolb/fabio/commit/fdaf1e966162e9dd3b347ffdd0647b39dc71a1a3 | Patch |
| https://github.com/fabiolb/fabio/releases/tag/v1.6.6 | Release Notes |
| https://github.com/fabiolb/fabio/security/advisories/GHSA-q7p4-7xjv-j3wf | Exploit Vendor Advisory |