CVE-2026-78662
Prevent DoS on deadlocked undecided channel in golang.org/x/crypto/ssh
Description
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.
INFO
Published Date :
Sept. 2, 2026, 8:17 p.m.
Last Modified :
Sept. 4, 2026, 4:33 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Add an atomic established state for channels.
- Set state when channel becomes usable.
- Drop packets until channel is established.
- Handle open confirmation/failure packets.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-78662.
| URL | Resource |
|---|---|
| https://go.dev/cl/826504 | Patch |
| https://go.dev/issue/81316 | Issue Tracking Vendor Advisory |
| https://groups.google.com/g/golang-announce/c/1y3fb2np35U | Mailing List Vendor Advisory |
| https://pkg.go.dev/vuln/GO-2026-6354 | Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-78662 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-78662
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-78662 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-78662 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 04, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:* versions up to (excluding) 0.56.0 Added Reference Type Go Project: https://go.dev/cl/826504 Types: Patch Added Reference Type Go Project: https://go.dev/issue/81316 Types: Issue Tracking, Vendor Advisory Added Reference Type Go Project: https://groups.google.com/g/golang-announce/c/1y3fb2np35U Types: Mailing List, Vendor Advisory Added Reference Type Go Project: https://pkg.go.dev/vuln/GO-2026-6354 Types: Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 03, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-770 Added SSVC {'id': 'CVE-2026-78662', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-03T13:19:47.340520Z'} -
New CVE Received by [email protected]
Sep. 02, 2026
Action Type Old Value New Value Added Description 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/78xxx/CVE-2026-78662.json">CVE-2026-78662</a> Added Reference https://go.dev/cl/826504 Added Reference https://go.dev/issue/81316 Added Reference https://groups.google.com/g/golang-announce/c/1y3fb2np35U Added Reference https://pkg.go.dev/vuln/GO-2026-6354