What is CVE-2025-4658?

CVE-2025-4658 is a critical-severity security vulnerability in github.com/openpubkey/opkssh (go), affecting versions < 0.5.0. It is fixed in 0.5.0.

Which versions of github.com/openpubkey/opkssh are affected by CVE-2025-4658?

github.com/openpubkey/opkssh (go) versions < 0.5.0 is affected.

Is there a fix for CVE-2025-4658?

Yes. CVE-2025-4658 is fixed in 0.5.0. Upgrade to this version or later.

Is CVE-2025-4658 exploitable, and should I be worried?

Whether CVE-2025-4658 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.

What actually determines whether CVE-2025-4658 is exploitable, and how bad it is?

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.

How do I fix CVE-2025-4658?

Upgrade github.com/openpubkey/opkssh to 0.5.0 or later.

CVE-2025-4658 in github.com/openpubkey/opkssh

Q: Which versions of github.com/openpubkey/opkssh are affected by CVE-2025-4658?

github.com/openpubkey/opkssh (go) versions < 0.5.0 is affected.

Q: Is there a fix for CVE-2025-4658?

Yes. CVE-2025-4658 is fixed in 0.5.0. Upgrade to this version or later.

Q: Is CVE-2025-4658 exploitable, and should I be worried?

Whether CVE-2025-4658 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.

Q: What actually determines whether CVE-2025-4658 is exploitable, and how bad it is?

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.

Q: How do I fix CVE-2025-4658?

Upgrade github.com/openpubkey/opkssh to 0.5.0 or later.

Summary

OPKSSH Vulnerable to Authentication Bypass

References

CVE-2025-4658

The upstream vulnerability in OpenPubkey is CVE-2025-3757 and has the security advisory https://github.com/openpubkey/openpubkey/security/advisories/GHSA-537f-gxgm-3jjq

Impact

Versions of OpenPubkey library prior to 0.10.0 contained a vulnerability that would allow a specially crafted JWS to bypass signature verification. As OPKSSH depends on the OpenPubkey library for authentication, this vulnerability in OpenPubkey also applies to OPKSSH versions prior to 0.5.0 and would allow an attacker to bypass OPKSSH authentication.

Affected versions

github.com/openpubkey/opkssh (< 0.5.0)

Security releases

github.com/openpubkey/opkssh → 0.5.0 (go)

Kodem intelligence

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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

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Remediation advice

The vulnerability does not exist in more recent versions of OPKSSH. his only impacts OPKSSH when used to verify ssh keys on a server, the OPKSSH client is unaffected. To remediate upgrade to a version of OPKSSH v0.5.0 or greater.

To determine if you are vulnerable run on your server:

opkssh --version

If the version is less than 0.5.0 you should upgrade. To upgrade to the latest version run:

wget -qO- "https://raw.githubusercontent.com/openpubkey/opkssh/main/scripts/install-linux.sh" | sudo bash

Frequently Asked Questions

What is CVE-2025-4658? CVE-2025-4658 is a critical-severity security vulnerability in github.com/openpubkey/opkssh (go), affecting versions < 0.5.0. It is fixed in 0.5.0.
Which versions of github.com/openpubkey/opkssh are affected by CVE-2025-4658? github.com/openpubkey/opkssh (go) versions < 0.5.0 is affected.
Is there a fix for CVE-2025-4658? Yes. CVE-2025-4658 is fixed in 0.5.0. Upgrade to this version or later.
Is CVE-2025-4658 exploitable, and should I be worried? Whether CVE-2025-4658 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
What actually determines whether CVE-2025-4658 is exploitable, and how bad it is? 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.
How do I fix CVE-2025-4658? Upgrade github.com/openpubkey/opkssh to 0.5.0 or later.