CVE-2026-56855

high

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.

References

https://pkg.go.dev/vuln/GO-2026-6355

https://groups.google.com/g/golang-announce/c/1y3fb2np35U

https://go.dev/issue/81317

https://go.dev/cl/826524

Details

Source: Mitre, NVD

Published: 2026-09-02

Updated: 2026-09-03

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00171