CVE-2026-25651Public exploitNetwork attack vector

Open redirect via unvalidated Host header

Published Feb 6, 2026 · Updated Feb 6, 2026

Open redirect in client-certificate-auth 0.2.1 and 0.3.0 allows remote attackers to redirect users via crafted Host headers. The opt-in redirectInsecure path builds an HTTPS Location value by concatenating the unvalidated Host header with the request URL. Exploitation requires HTTP to reach the Node.js application without x-forwarded-proto set to https and user interaction with the resulting redirect.

CVSS severity6.1
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Open redirect in client-certificate-auth 0.2.1 and 0.3.0 allows remote attackers to redirect users via crafted Host headers. The opt-in redirectInsecure path builds an HTTPS Location value by concatenating the unvalidated Host header with the request URL. Exploitation requires HTTP to reach the Node.js application without x-forwarded-proto set to https and user interaction with the resulting redirect.

The record

CVE
CVE-2026-25651
Published
Feb 6, 2026
Updated
Feb 6, 2026
Vendor
Tony Gies
Product
client-certificate-auth
Classifications
CWE-601, CAPEC-178, T1566.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.2.1, < 1.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tony Gies · client-certificate-authversion=>= 0.2.1, < 1.0.0

Published CVSS scores

6.1GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-601URL Redirection to Untrusted Site ('Open Redirect')
CAPEC-178Cross-Site Flashing
T1566.002Spearphishing Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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