CVE-2026-56854
Source-address critical option not enforced for non-public-key auth callbacks in golang.org/x/crypto/ssh
Description
The source-address critical option in the Permissions returned by an authentication callback was only enforced for the PublicKeyCallback and VerifiedPublicKeyCallback paths, extending the fix for CVE-2026-46595. Permissions returned by the PasswordCallback, KeyboardInteractiveCallback, NoClientAuthCallback, and GSSAPIWithMICConfig.AllowLogin callbacks were not validated against the client's remote address, so a source-address restriction set by those callbacks was silently ignored. The check is now applied to the Permissions returned by any authentication callback.
INFO
Published Date :
Aug. 28, 2026, 4:18 p.m.
Last Modified :
Aug. 28, 2026, 4:18 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-56854
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
- Apply the latest security patches and updates.
- Ensure all authentication callbacks validate client addresses.
- Verify the permissions are enforced correctly.
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-2026-56854.
| URL | Resource |
|---|---|
| https://go.dev/cl/797040 | |
| https://go.dev/issue/80213 | |
| https://pkg.go.dev/vuln/GO-2026-6303 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56854 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-2026-56854
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-2026-56854 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56854 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]
Aug. 28, 2026
Action Type Old Value New Value Added Description The source-address critical option in the Permissions returned by an authentication callback was only enforced for the PublicKeyCallback and VerifiedPublicKeyCallback paths, extending the fix for CVE-2026-46595. Permissions returned by the PasswordCallback, KeyboardInteractiveCallback, NoClientAuthCallback, and GSSAPIWithMICConfig.AllowLogin callbacks were not validated against the client's remote address, so a source-address restriction set by those callbacks was silently ignored. The check is now applied to the Permissions returned by any authentication callback. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/56xxx/CVE-2026-56854.json">CVE-2026-56854</a> Added Reference https://go.dev/cl/797040 Added Reference https://go.dev/issue/80213 Added Reference https://pkg.go.dev/vuln/GO-2026-6303