CVE-2025-4673Network attack vector

Proxy credential disclosure via cross-origin redirects

Published Jun 11, 2025 · Updated Jun 11, 2025

Header disclosure in Go standard library net/http before 1.23.10 and 1.24.0-0 before 1.24.4 allows remote attackers to read proxy credentials. Client.makeHeadersCopier omits Proxy-Authorization and Proxy-Authenticate from the sensitive-header set, so redirect requests copy them to another origin. Exploitation requires a client to set either proxy header, follow an attacker-controlled cross-origin redirect, and send the redirected request; exposure is limited to the header contents.

CVSS severity6.8
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Header disclosure in Go standard library net/http before 1.23.10 and 1.24.0-0 before 1.24.4 allows remote attackers to read proxy credentials. Client.makeHeadersCopier omits Proxy-Authorization and Proxy-Authenticate from the sensitive-header set, so redirect requests copy them to another origin. Exploitation requires a client to set either proxy header, follow an attacker-controlled cross-origin redirect, and send the redirected request; exposure is limited to the header contents.

The record

CVE
CVE-2025-4673
Published
Jun 11, 2025
Updated
Jun 11, 2025
Vendor
Go standard library
Product
net/http
Classifications
CWE-201, T1212
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 11, 2025Record 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 <1.23.10
  2. Affected versionversion=1.24.0-0 <1.24.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · net/httpversion=0 <1.23.10; version=1.24.0-0 <1.24.4

Published CVSS scores

6.8GitHub Advisory DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-201Insertion of Sensitive Information Into Sent Data
T1212Exploitation for Credential Access

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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