Unexpected session resumption in crypto/tls_CVE-2025-68121

4.8 / 10

MEDIUM

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

Description

During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may happen when a user calls Config.Clone and mutates the returned Config, or uses Config.GetConfigForClient. This can cause a client to resume a session with a server that it would not have resumed with during the initial handshake, or cause a server to resume a session with a client that it would not have resumed with during the initial handshake.

Basic Information

ID CVE-2025-68121

Source Go

Published Feb 5, 2026 at 17:48

Modified Feb 6, 2026 at 15:35

Affected Product

Vendor Go standard library

Product crypto/tls

Affected Versions Go standard library crypto/tls 0
Go standard library crypto/tls 1.25.0-0
Go standard library crypto/tls 1.26.0-rc.1

CWE Classification

CWE-295

References

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    "published": "2026-02-05T17:48:44.141Z",
    "modified": "2026-02-06T15:35:32.823Z",
    "type": "cve",
    "title": "Unexpected session resumption in crypto/tls",
    "source": "Go",
    "references": "https://groups.google.com/g/golang-announce/c/K09ubi9FQFk\nhttps://go.dev/cl/737700\nhttps://go.dev/issue/77217\nhttps://pkg.go.dev/vuln/GO-2026-4337",
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