What is CVE-2026-34210?

CVE-2026-34210 is a medium-severity security vulnerability in mppx (npm), affecting versions < 0.4.11. It is fixed in 0.4.11.

Which versions of mppx are affected by CVE-2026-34210?

mppx (npm) versions < 0.4.11 is affected.

Is there a fix for CVE-2026-34210?

Yes. CVE-2026-34210 is fixed in 0.4.11. Upgrade to this version or later.

Is CVE-2026-34210 exploitable, and should I be worried?

Whether CVE-2026-34210 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-2026-34210 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-2026-34210?

Upgrade mppx to 0.4.11 or later.

CVE-2026-34210 in mppx | Intelligent Application Security

Q: Which versions of mppx are affected by CVE-2026-34210?

mppx (npm) versions < 0.4.11 is affected.

Q: Is there a fix for CVE-2026-34210?

Yes. CVE-2026-34210 is fixed in 0.4.11. Upgrade to this version or later.

Q: Is CVE-2026-34210 exploitable, and should I be worried?

Whether CVE-2026-34210 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-2026-34210 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-2026-34210?

Upgrade mppx to 0.4.11 or later.

Summary

Workarounds

There are no workarounds available for this vulnerability.

Impact

The stripe/charge payment method did not check Stripe's Idempotent-Replayed response header when creating PaymentIntents. An attacker could replay a valid credential containing the same spt token against a new challenge, and the server would accept the replayed Stripe PaymentIntent as a new successful payment without actually charging the customer again. This allowed an attacker to pay once and consume unlimited resources by replaying the credential.

Affected versions

mppx (< 0.4.11)

Security releases

mppx → 0.4.11 (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.

See it in your environment

Remediation advice

Fixed in 0.4.11. The server now checks the Idempotent-Replayed header and rejects replayed PaymentIntents.

Frequently Asked Questions

What is CVE-2026-34210? CVE-2026-34210 is a medium-severity security vulnerability in mppx (npm), affecting versions < 0.4.11. It is fixed in 0.4.11.
Which versions of mppx are affected by CVE-2026-34210? mppx (npm) versions < 0.4.11 is affected.
Is there a fix for CVE-2026-34210? Yes. CVE-2026-34210 is fixed in 0.4.11. Upgrade to this version or later.
Is CVE-2026-34210 exploitable, and should I be worried? Whether CVE-2026-34210 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-2026-34210 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-2026-34210? Upgrade mppx to 0.4.11 or later.

Other vulnerabilities in mppx

CVE-2026-34210