What is CVE-2022-31103?

CVE-2022-31103 is a high-severity security vulnerability in lettersanitizer (npm), affecting versions < 1.0.2. It is fixed in 1.0.2.

How severe is CVE-2022-31103?

CVE-2022-31103 has a CVSS score of 7.5 (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 lettersanitizer are affected by CVE-2022-31103?

lettersanitizer (npm) versions < 1.0.2 is affected.

Is there a fix for CVE-2022-31103?

Yes. CVE-2022-31103 is fixed in 1.0.2. Upgrade to this version or later.

Is CVE-2022-31103 exploitable, and should I be worried?

Whether CVE-2022-31103 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-2022-31103 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-2022-31103?

Upgrade lettersanitizer to 1.0.2 or later.

CVE-2022-31103 in lettersanitizer

Q: How severe is CVE-2022-31103?

CVE-2022-31103 has a CVSS score of 7.5 (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 lettersanitizer are affected by CVE-2022-31103?

lettersanitizer (npm) versions < 1.0.2 is affected.

Q: Is there a fix for CVE-2022-31103?

Yes. CVE-2022-31103 is fixed in 1.0.2. Upgrade to this version or later.

Q: Is CVE-2022-31103 exploitable, and should I be worried?

Whether CVE-2022-31103 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-2022-31103 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-2022-31103?

Upgrade lettersanitizer to 1.0.2 or later.

Summary

Improper handling of CSS at-rules in lettersanitizer

Workarounds

There is no workaround besides upgrading.

References

The issue was originally reported in the react-letter repository: https://github.com/mat-sz/react-letter/issues/17

For more information

If you have any questions or comments about this advisory:

Open an issue in lettersanitizer
Email me at [email protected]

Impact

All versions of lettersanitizer below 1.0.2 are affected by a denial of service issue when processing a CSS at-rule @keyframes.

This package is depended on by react-letter, therefore everyone using react-letter is also at risk.

CVE-2022-31103 has a CVSS score of 7.5 (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 (1.0.2); upgrading removes the vulnerable code path.

Affected versions

lettersanitizer (< 1.0.2)

Security releases

lettersanitizer → 1.0.2 (npm)

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 problem has been patched in version 1.0.2.

Frequently Asked Questions

What is CVE-2022-31103? CVE-2022-31103 is a high-severity security vulnerability in lettersanitizer (npm), affecting versions < 1.0.2. It is fixed in 1.0.2.
How severe is CVE-2022-31103? CVE-2022-31103 has a CVSS score of 7.5 (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 lettersanitizer are affected by CVE-2022-31103? lettersanitizer (npm) versions < 1.0.2 is affected.
Is there a fix for CVE-2022-31103? Yes. CVE-2022-31103 is fixed in 1.0.2. Upgrade to this version or later.
Is CVE-2022-31103 exploitable, and should I be worried? Whether CVE-2022-31103 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-2022-31103 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-2022-31103? Upgrade lettersanitizer to 1.0.2 or later.