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.
Affected products
golang: crypto
References4
- go.dev/issue/81317 Issue TrackingVendor Advisory
- groups.google.com/g/golang-announce/c/1y3fb2np35U Mailing ListVendor Advisory
- pkg.go.dev/vuln/GO-2026-6355 Vendor Advisory
- go.dev/cl/826524 Patch
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 43 · as of 3 November 2026
- CWE
- CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.