CVE-2026-42505

MEDIUM CVSS 3.1: 5.3 EPSS 0.38%
Updated Sep 16, 2026
Golang
Parameter Value
CVSS 5.3 (MEDIUM)
Affected Versions 1.26.0 — 1.26.5
Fixed In 1.25.12
Type CWE-201
Vendor Golang
Public PoC No

Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
Low
Partial data leak
Integrity
None
No data modification
Availability
None
No disruption

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 3

Configuration From (including) Up to (excluding)
Golang Go
cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
1.25.12
Golang Go
cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*
1.26.0 1.26.5
Golang Go
cpe:2.3:a:golang:go:1.27:rc1:*:*:*:*:*:*