VulnerabilityAnalyzed
CVE-2026-56855
Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection.
HIGH 7.5EPSS 0.38%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.38% probability · 31th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- golang/crypto
- Source
- security@golang.org
References
- https://go.dev/cl/826524Patch
- https://go.dev/issue/81317Issue Tracking, Vendor Advisory
- https://groups.google.com/g/golang-announce/c/1y3fb2np35UMailing List, Vendor Advisory
- https://pkg.go.dev/vuln/GO-2026-6355Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.