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Stripe charge credential replay via missing idempotency check within mppx

Moderate
tmm published GHSA-8mhj-rffc-rcvw Mar 26, 2026

Package

npm mppx (npm)

Affected versions

<0.4.11

Patched versions

0.4.11

Description

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.

Patches

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

Workarounds

There are no workarounds available for this vulnerability.

References

N/A

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

CVE ID

CVE-2026-34210

Weaknesses

Incorrect Comparison

The product compares two entities in a security-relevant context, but the comparison is incorrect, which may lead to resultant weaknesses. Learn more on MITRE.

Credits