ALPN Negotiation Flaw in Go Programming Language
CVE-2025-58189

5.3MEDIUM

Key Information:

Vendor

Go Standard Library

Status
Crypto/tls
Vendor
CVE Published:
29 October 2025

What is CVE-2025-58189?

A security issue in the Go programming language arises during the ALPN negotiation process. When the conn.Handshake operation fails, it improperly exposes attacker-controlled information, specifically the ALPN protocols presented by the client. This flaw can be exploited to expose sensitive data, potentially undermining the application's security. Developers using affected versions of Go should apply the necessary patches to mitigate this risk.

Affected Version(s)

crypto/tls 0 < 1.24.8

crypto/tls 1.25.0 < 1.25.2

References

https://go.dev/cl/707776
https://go.dev/issue/75652
https://groups.google.com/g/golang-announce/c/4Emdl2iQ_bI

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

National Cyber Security Centre Finland
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