CVE-2026-39834
Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh
Description
When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation.
INFO
Published Date :
May 22, 2026, 4:16 a.m.
Last Modified :
May 22, 2026, 4:16 a.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-39834
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the software to prevent integer overflow during large data writes.
- Ensure payload size calculations use int64 to avoid truncation.
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-2026-39834.
| URL | Resource |
|---|---|
| https://go.dev/cl/781663 | |
| https://go.dev/issue/79567 | |
| https://groups.google.com/g/golang-announce/c/a082jnz-LvI | |
| https://pkg.go.dev/vuln/GO-2026-5020 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-39834 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-2026-39834
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-2026-39834 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-39834 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.
-
New CVE Received by [email protected]
May. 22, 2026
Action Type Old Value New Value Added Description When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation. Added Reference https://go.dev/cl/781663 Added Reference https://go.dev/issue/79567 Added Reference https://groups.google.com/g/golang-announce/c/a082jnz-LvI Added Reference https://pkg.go.dev/vuln/GO-2026-5020