CVE-2026-39830
Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh
Description
A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.
INFO
Published Date :
May 22, 2026, 4:16 a.m.
Last Modified :
June 2, 2026, 4:33 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Discard unsolicited SSH global request responses.
- Ensure read loops are not blocked.
- Release blocked goroutines by calling Close().
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-2026-39830.
| URL | Resource |
|---|---|
| https://go.dev/cl/781640 | Issue Tracking |
| https://go.dev/cl/781664 | Issue Tracking |
| https://go.dev/issue/79564 | Issue Tracking |
| https://groups.google.com/g/golang-announce/c/a082jnz-LvI | Mailing List |
| https://pkg.go.dev/vuln/GO-2026-5017 | 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-2026-39830 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-2026-39830
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-2026-39830 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-39830 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]
Jun. 02, 2026
Action Type Old Value New Value Added CWE CWE-119 Added CPE Configuration OR *cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:* versions up to (excluding) 0.52.0 Added Reference Type Go Project: https://go.dev/cl/781640 Types: Issue Tracking Added Reference Type Go Project: https://go.dev/cl/781664 Types: Issue Tracking Added Reference Type Go Project: https://go.dev/issue/79564 Types: Issue Tracking Added Reference Type Go Project: https://groups.google.com/g/golang-announce/c/a082jnz-LvI Types: Mailing List Added Reference Type Go Project: https://pkg.go.dev/vuln/GO-2026-5017 Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 22, 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:H -
New CVE Received by [email protected]
May. 22, 2026
Action Type Old Value New Value Added Description A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded. Added Reference https://go.dev/cl/781640 Added Reference https://go.dev/cl/781664 Added Reference https://go.dev/issue/79564 Added Reference https://groups.google.com/g/golang-announce/c/a082jnz-LvI Added Reference https://pkg.go.dev/vuln/GO-2026-5017