CVE record
CVE-2026-39832
Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent
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.
CVE evidence
Known exploitation
Not listed in fetched KEV catalog
Absence from the fetched catalog does not establish that exploitation has not occurred.
Severity
critical
CVSS 9.1 ยท CVSS_V3
Affected packages
1
Supported package records returned by OSV. Vendor and product names are not used to infer matches.
OSV package mapping
Affected open-source packages
| Package | Ecosystem | Fixed versions |
|---|---|---|
| golang.org/x/crypto | go | 0.52.0 |