What is CVE-2022-39254?

CVE-2022-39254 is a high-severity improper authentication vulnerability in matrix-nio (pip), affecting versions < 0.20. It is fixed in 0.20. The application does not adequately verify the identity of a user, device, or process before granting access.

How severe is CVE-2022-39254?

CVE-2022-39254 has a CVSS score of 8.6 (High). 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.

Which versions of matrix-nio are affected by CVE-2022-39254?

matrix-nio (pip) versions < 0.20 is affected.

Is there a fix for CVE-2022-39254?

Yes. CVE-2022-39254 is fixed in 0.20. Upgrade to this version or later.

Is CVE-2022-39254 exploitable, and should I be worried?

Whether CVE-2022-39254 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-2022-39254 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.

CVE-2022-39254 in matrix-nio

Q: How severe is CVE-2022-39254?

CVE-2022-39254 has a CVSS score of 8.6 (High). 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.

Q: Which versions of matrix-nio are affected by CVE-2022-39254?

matrix-nio (pip) versions < 0.20 is affected.

Q: Is there a fix for CVE-2022-39254?

Yes. CVE-2022-39254 is fixed in 0.20. Upgrade to this version or later.

Q: Is CVE-2022-39254 exploitable, and should I be worried?

Whether CVE-2022-39254 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-2022-39254 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-2022-39254?

Upgrade matrix-nio to 0.20 or later.

Summary

When matrix-nio receives forwarded room keys, the receiver doesn't check if it requested the key from the forwarder

When matrix-nio before 0.20 requests a room key from our devices, it correctly accepts key forwards only if they are a response to a previous request. However, it doesn't check that the device that responded matches the device the key was requested from.

This allows a malicious homeserver to insert room keys of questionable validity into the key store in some situations, potentially assisting in an impersonation attack.

For more information

If you have any questions or comments about this advisory, e-mail us at [email protected].

Impact

The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.

CVE-2022-39254 has a CVSS score of 8.6 (High). 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 (0.20); upgrading removes the vulnerable code path.

Affected versions

matrix-nio (< 0.20)

Security releases

matrix-nio → 0.20 (pip)

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

Upgrade matrix-nio to 0.20 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2022-39254? CVE-2022-39254 is a high-severity improper authentication vulnerability in matrix-nio (pip), affecting versions < 0.20. It is fixed in 0.20. The application does not adequately verify the identity of a user, device, or process before granting access.
How severe is CVE-2022-39254? CVE-2022-39254 has a CVSS score of 8.6 (High). 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.
Which versions of matrix-nio are affected by CVE-2022-39254? matrix-nio (pip) versions < 0.20 is affected.
Is there a fix for CVE-2022-39254? Yes. CVE-2022-39254 is fixed in 0.20. Upgrade to this version or later.
Is CVE-2022-39254 exploitable, and should I be worried? Whether CVE-2022-39254 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-2022-39254 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-2022-39254? Upgrade matrix-nio to 0.20 or later.