CVE-2026-39832 is a critical-severity insecure deserialization vulnerability in golang.org/x/crypto/ssh/agent (go), affecting versions < 0.52.0. It is fixed in 0.52.0.
When adding a key to a remote agent constraint extensions such as [email protected] 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.
Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect. Typical impact: arbitrary code execution or logic abuse.
CVE-2026-39832 has a CVSS score of 9.1 (Critical). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (0.52.0). Upgrading removes the vulnerable code path.
go
golang.org/x/crypto/ssh/agent (< 0.52.0)golang.org/x/crypto/ssh/agent → 0.52.0 (go)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's Application Detection and Response identifies whether CVE-2026-39832 is reachable in your applications. Explore runtime application protection for your team.
See if CVE-2026-39832 is reachable in your applications. Get a demo
Already deployed Kodem? See CVE-2026-39832 in your environment →Upgrade golang.org/x/crypto/ssh/agent to 0.52.0 or later to resolve this vulnerability.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-39832 is a critical-severity insecure deserialization vulnerability in golang.org/x/crypto/ssh/agent (go), affecting versions < 0.52.0. It is fixed in 0.52.0. Untrusted serialized data is processed by a deserializer that can instantiate arbitrary objects or execute code as a side effect.
CVE-2026-39832 has a CVSS score of 9.1 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
golang.org/x/crypto/ssh/agent (go) versions < 0.52.0 is affected.
Yes. CVE-2026-39832 is fixed in 0.52.0. Upgrade to this version or later.
Whether CVE-2026-39832 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade golang.org/x/crypto/ssh/agent to 0.52.0 or later.