CVE-2026-42505

Published: Jul 8, 2026Modified: Jul 13, 2026

5.3

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Exploitability: 3.9 / Impact: 1.4

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary)

Description

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.

Affected (3)

Products: Golang: Go

Golang

1 product

Configuration A

3 vulnerable

Vulnerable Software	Affected Versions
Golang Go	Before 1.25.12
Golang Go	From 1.26.0 to 1.26.5
Golang Go	Version 1.27 rc1

Related CWEs

CWE-201

Insertion of Sensitive Information Into Sent Data

The code transmits data to another actor, but a portion of the data includes sensitive information that should not be accessible to that actor.

References (4)

https://go.dev/cl/775960

Source: security@golang.org

Patch

https://go.dev/issue/79282

Source: security@golang.org

Issue TrackingPatch

https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc

Source: security@golang.org

Mailing ListRelease NotesVendor Advisory

https://pkg.go.dev/vuln/GO-2026-5856

Source: security@golang.org

Vendor Advisory

Timeline

No history available yet.