Unexpected session resumption in crypto/tls
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.
GO-2026-4337
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GO-2026-4337
stdlib
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.24.13
Source reference:
/affected/0/ranges1.25.7Source reference:
/affected/0/ranges1.26.0-rc.3Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.24.13"
},
{
"introduced": "1.25.0-0"
},
{
"fixed": "1.25.7"
},
{
"introduced": "1.26.0-rc.1"
},
{
"fixed": "1.26.0-rc.3"
}
]
}
],
"package": {
"name": "stdlib",
"purl": "pkg:golang/stdlib",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://vuln.go.dev/ID/GO-2026-4337.json"
},
"ecosystem_specific": {
"imports": [
{
"path": "crypto/tls",
"symbols": [
"Conn.Handshake",
"Conn.HandshakeContext",
"Conn.Read",
"Conn.Write",
"Conn.handshakeContext",
"Dial",
"DialWithDialer",
"Dialer.Dial",
"Dialer.DialContext",
"QUICConn.Start"
]
}
]
}
}
]- Related CVEs
- CVE-2025-68121
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #27680 · Revision 1
- Added to Heist Feed
- Publisher date