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.
Scores
CVSS v3
10.0
EPSS
0.0002
EPSS Percentile
4.6%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
total
Details
CWE
CWE-295
Status
published
Products (5)
Go standard library/crypto/tls
< 1.24.13
Go standard library/crypto/tls
1.25.0-0 - 1.25.7
Go standard library/crypto/tls
1.26.0-rc.1 - 1.26.0-rc.3
golang/go
1.26.0 rc1 (2 CPE variants)
golang/go
< 1.24.13
Published
Feb 05, 2026
Tracked Since
Feb 18, 2026