CVE-2026-56855
Last modified
CVE-2026-56855 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.38% chance of exploitation in the next 30 days.
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.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Golang | Crypto | < 0.56.0 |
References
- 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
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
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