Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh
Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.
GO-2026-6355
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-2026-6355
golang.org/x/crypto
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 0.56.0
Source 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": "0.56.0"
}
]
}
],
"package": {
"name": "golang.org/x/crypto",
"purl": "pkg:golang/golang.org/x/crypto",
"ecosystem": "Go"
},
"database_specific": {
"source": "https://vuln.go.dev/ID/GO-2026-6355.json"
},
"ecosystem_specific": {
"imports": [
{
"path": "golang.org/x/crypto/ssh",
"symbols": [
"Dial",
"NewClientConn",
"NewControlClientConn",
"NewServerConn",
"channel.handlePacket"
]
}
]
}
}
]- Related CVEs
- CVE-2026-56855
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #13684 · Revision 1
- Added to Heist Feed
- Publisher date