CVE-2026-39829
golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via crafted public key with excessive parameters
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 22, 2026
Updated · November 5, 2026
Description
A flaw was found in golang.org/x/crypto/ssh. The RSA and DSA public key parsers in the affected component did not enforce size limits on key parameters. This vulnerability allows an unauthenticated client to provide a crafted public key with an excessively large modulus or DSA parameter during public key authentication. Successful exploitation could lead to a denial of service (DoS) due to prolonged CPU consumption during signature verification.
Statement
This vulnerability in golang.org/x/crypto/ssh is rated as Important. An unauthenticated remote attacker could trigger a denial of service by providing a specially crafted public key with excessively large parameters during SSH public key authentication. This could lead to prolonged CPU consumption on the server, impacting service availability.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-1284 · Improper Validation of Specified Quantity in Input