What is CVE-2022-39227?

CVE-2022-39227 is a critical-severity security vulnerability in python-jwt (pip), affecting versions < 3.3.4. It is fixed in 3.3.4.

How severe is CVE-2022-39227?

CVE-2022-39227 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.

Which versions of python-jwt are affected by CVE-2022-39227?

python-jwt (pip) versions < 3.3.4 is affected.

Is there a fix for CVE-2022-39227?

Yes. CVE-2022-39227 is fixed in 3.3.4. Upgrade to this version or later.

Is CVE-2022-39227 exploitable, and should I be worried?

Whether CVE-2022-39227 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-2022-39227 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-2022-39227?

Upgrade python-jwt to 3.3.4 or later.

CVE-2022-39227 in python-jwt

Q: How severe is CVE-2022-39227?

CVE-2022-39227 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.

Q: Which versions of python-jwt are affected by CVE-2022-39227?

python-jwt (pip) versions < 3.3.4 is affected.

Q: Is there a fix for CVE-2022-39227?

Yes. CVE-2022-39227 is fixed in 3.3.4. Upgrade to this version or later.

Q: Is CVE-2022-39227 exploitable, and should I be worried?

Whether CVE-2022-39227 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-2022-39227 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-2022-39227?

Upgrade python-jwt to 3.3.4 or later.

Summary

python-jwt vulnerable to token forgery with new claims

Workarounds

None

References

Found by Tom Tervoort
https://github.com/pypa/advisory-database/blob/main/vulns/python-jwt/PYSEC-2022-259.yaml

More information

The vulnerability allows an attacker, who possesses a single valid JWT, to create a new token with forged claims that the verify_jwt function will accept as valid.

The issue is caused by an inconsistency between the JWT parsers used by python-jwt and its dependency jwcrypto. By mixing compact and JSON representations, an attacker can trick jwcrypto of parsing different claims than those over which a signature is validated by jwcrypto.

Testing the fix has been added as an automated unit test to python-jwt.

If you have any questions or comments about this advisory, please open an issue in python-jwt

Impact

An attacker who obtains a JWT can arbitrarily forge its contents without knowing the secret key. Depending on the application, this may for example enable the attacker to spoof other user's identities, hijack their sessions, or bypass authentication.

CVE-2022-39227 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 (3.3.4); upgrading removes the vulnerable code path.

Affected versions

python-jwt (< 3.3.4)

Security releases

python-jwt → 3.3.4 (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

Users should upgrade to version 3.3.4
Fixed by: https://github.com/davedoesdev/python-jwt/commit/88ad9e67c53aa5f7c43ec4aa52ed34b7930068c9

Frequently Asked Questions

What is CVE-2022-39227? CVE-2022-39227 is a critical-severity security vulnerability in python-jwt (pip), affecting versions < 3.3.4. It is fixed in 3.3.4.
How severe is CVE-2022-39227? CVE-2022-39227 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.
Which versions of python-jwt are affected by CVE-2022-39227? python-jwt (pip) versions < 3.3.4 is affected.
Is there a fix for CVE-2022-39227? Yes. CVE-2022-39227 is fixed in 3.3.4. Upgrade to this version or later.
Is CVE-2022-39227 exploitable, and should I be worried? Whether CVE-2022-39227 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-2022-39227 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-2022-39227? Upgrade python-jwt to 3.3.4 or later.