CVE-2026-42508
Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts
Description
Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.
INFO
Published Date :
May 22, 2026, 4:16 a.m.
Last Modified :
May 28, 2026, 2:47 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
- Update software to version with signature key revocation checks.
- Verify that both 'key' and 'key.SignatureKey' are checked.
- Ensure CA key revocation policies are enforced.
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-2026-42508.
| URL | Resource |
|---|---|
| https://go.dev/cl/781220 | Issue Tracking |
| https://go.dev/issue/79568 | Issue Tracking |
| https://groups.google.com/g/golang-announce/c/a082jnz-LvI | Mailing List |
| https://pkg.go.dev/vuln/GO-2026-5021 | 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-2026-42508 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-2026-42508
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-2026-42508 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42508 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]
May. 28, 2026
Action Type Old Value New Value Added CWE CWE-295 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/781220 Types: Issue Tracking Added Reference Type Go Project: https://go.dev/issue/79568 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-2026-5021 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:H/A:N -
New CVE Received by [email protected]
May. 22, 2026
Action Type Old Value New Value Added Description Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked. Added Reference https://go.dev/cl/781220 Added Reference https://go.dev/issue/79568 Added Reference https://groups.google.com/g/golang-announce/c/a082jnz-LvI Added Reference https://pkg.go.dev/vuln/GO-2026-5021