Review reviewCritical

CVE-2026-39832

golang.org/x/crypto golang.org/x/crypto/ssh/agent, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8

When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.

CVSS: 9.1
EPSS: 0.60%
CISA KEV: Not listed
Published: 2026.05.22

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.60%

Technical severityCVSS 9.1

Vulnerability overview

Affected product and versions

Product: golang.org/x/crypto golang.org/x/crypto/ssh/agent, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8
Affected versions: < 0.52.0
Fixed versions: 0.52.0

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that golang.org/x/crypto golang.org/x/crypto/ssh/agent, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE: CWE-281, CWE-502