Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection.
Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.
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.
This PR contains the following updates:
| Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [golang.org/x/crypto](https://pkg.go.dev/golang.org/x/crypto) | [`v0.55.0` → `v0.56.0`](https://cs.opensource.google/go/x/crypto/+/refs/tags/v0.55.0...refs/tags/v0.56.0) |  |  |
---
### Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh
[CVE-2026-78662](https://nvd.nist.gov/vuln/detail/CVE-2026-78662) / [GO-2026-6354](https://pkg.go.dev/vuln/GO-2026-6354)
<details>
<summary>More information</summary>
#### Details
Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection.
Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.
#### Severity
Unknown
#### References
- [https://go.dev/issue/81316](https://go.dev/issue/81316)
- [https://go.dev/cl/826504](https://go.dev/cl/826504)
- [https://groups.google.com/g/golang-announce/c/1y3fb2np35U](https://groups.google.com/g/golang-announce/c/1y3fb2np35U)
This data is provided by [OSV](https://osv.dev/vulnerability/GO-2026-6354) and the [Go Vulnerability Database](https://github.com/golang/vulndb) ([CC-BY 4.0](https://github.com/golang/vulndb#license)).
</details>
---
### Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh
[CVE-2026-56855](https://nvd.nist.gov/vuln/detail/CVE-2026-56855) / [GO-2026-6355](https://pkg.go.dev/vuln/GO-2026-6355)
<details>
<summary>More information</summary>
#### Details
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.
#### Severity
Unknown
#### References
- [https://go.dev/issue/81317](https://go.dev/issue/81317)
- [https://go.dev/cl/826524](https://go.dev/cl/826524)
- [https://groups.google.com/g/golang-announce/c/1y3fb2np35U](https://groups.google.com/g/golang-announce/c/1y3fb2np35U)
This data is provided by [OSV](https://osv.dev/vulnerability/GO-2026-6355) and the [Go Vulnerability Database](https://github.com/golang/vulndb) ([CC-BY 4.0](https://github.com/golang/vulndb#license)).
</details>
---
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This PR contains the following updates:
v0.55.0→v0.56.0Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh
CVE-2026-78662 / GO-2026-6354
More information
Details
Previously, a channel registered in the mux's chanList is not usable until it is established. A malicious peer was able flood the channel's incomingRequests, deadlocking the entire connection.
Now, we add an atomic established state, set when a channel becomes usable. Until such a time, handlePacket drops every packet other than the open confirmation/failure, without blocking and without tearing down the connection.
Severity
Unknown
References
This data is provided by OSV and the Go Vulnerability Database (CC-BY 4.0).
Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh
CVE-2026-56855 / GO-2026-6355
More information
Details
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.
Severity
Unknown
References
This data is provided by OSV and the Go Vulnerability Database (CC-BY 4.0).
Configuration
📅 Schedule: (UTC)
🚦 Automerge: Enabled.
♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
This PR has been generated by Mend Renovate CLI.