Review reviewCritical

CVE-2026-39833

golang.org/x/crypto golang.org/x/crypto/ssh/agent, crypto

The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested.

CVSS: 9.1
EPSS: 0.41%
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 probability0.41%

Technical severityCVSS 9.1

Vulnerability overview

Affected product and versions

Product: golang.org/x/crypto golang.org/x/crypto/ssh/agent, crypto
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, crypto 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-862