CVE-2026-56855

Description

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.

CVSS Vector

References

• https://go.dev/cl/826524
• https://go.dev/issue/81317
• https://groups.google.com/g/golang-announce/c/1y3fb2np35U
• https://pkg.go.dev/vuln/GO-2026-6355