CVE-2026-55219: Paymenter/paymenter Paymenter Has Race Condition Vulnerability

MODERATE
Advisory Identifier: GHSA-pgcq-8grm-5rx9
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CVSS 5.3
CWE-362
Published
Advisory Summary

CVE-2026-55219 is a MODERATE (CVSS 5.3) paymenter has race condition vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Paymenter/paymenter libraries in the Packagist ecosystem. The issue involves paymenter has race condition in paywithcredit() that enables credit double-spend. Remediation is available by upgrading affected packages to version 1.5.5.

CVE-2026-55219 at a Glance

CVE Identifier CVE-2026-55219
GHSA Identifier GHSA-pgcq-8grm-5rx9
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Paymenter/paymenter
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-55219

To remediate this vulnerability, upgrade all affected Paymenter/paymenter dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

paymenter/paymenter fixed: 1.5.5 
Upgrade paymenter/paymenter to 1.5.5
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for paymenter/paymenter

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-55219, inspect your project dependencies for Paymenter/paymenter:

inspect dependencies for paymenter/paymenter

Analyze the terminal output to locate any version of Paymenter/paymenter in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.5.5), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In Paymenter/paymenter, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary The credit payment implementation in `app/Livewire/Invoices/Show.php` executes a pessimistic row lock (`lockForUpdate()`) outside of an active database transaction. Because MySQL/MariaDB requires an enclosing transaction to enforce row-level locks, the guard is ineffective. Concurrent payment requests can exploit this race condition to read the same credit balance simultaneously, allowing users to pay multiple invoices using the same credit balance. ### Technical Details The issue occurs because the application attempts to lock the user's credit balance row in the database (`lockForUpdate()`) without opening a database transaction. In database systems like MySQL, a row lock only works inside a formal transaction; without one, the lock is completely ignored. Because there is no active lock, two payment requests sent at the exact same millisecond can look at the database at the same time. Both requests see the original credit balance, decide it is sufficient, and approve the payment. ### Impact This race condition allows any authenticated user with a valid credit balance to bypass balance restrictions and settle multiple pending invoices simultaneously for the cost of a single invoice. Because the payment processes successfully through ExtensionHelper::addPayment(), the application provisions the corresponding services or digital goods, resulting in direct financial or resource loss to the platform.

CVE-2026-55219 Affected Paymenter/paymenter Versions

1 component(s)
Fixed Versions:
1.5.5
Product / Package Ecosystem Affected Versions Fixed Version
paymenter/paymenter
 Packagist
< 1.5.5
1.5.5

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Paymenter/Paymenter/security/advisories/GHSA-pgcq-8grm-5rx9
Paymenter/paymenter Source Repository REPOSITORY
https://github.com/Paymenter/Paymenter

Frequently Asked Questions

What is CVE-2026-55219?
CVE-2026-55219 is a security vulnerability in Paymenter/paymenter involving Paymenter has race condition in payWithCredit() that enables credit double-spend under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Paymenter/paymenter versions are affected?
Affected versions include releases prior to 1.5.5 across affected packages: paymenter/paymenter.
What version fixes CVE-2026-55219?
Upgrading to 1.5.5 (or the latest patched release for your respective branch) resolves the vulnerability.
Is paymenter/paymenter affected?
Yes, paymenter/paymenter is affected in releases prior to 1.5.5. Upgrade your dependency to 1.5.5 or later.
What is the CVSS score of CVE-2026-55219?
CVE-2026-55219 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2026-55219?
CVE-2026-55219 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check Packagist dependencies for CVE-2026-55219?
Run the dependency tree command: 'inspect dependencies for paymenter/paymenter'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-pgcq-8grm-5rx9",
  "modified" : "2026-06-30T19:11:24Z",
  "published" : "2026-06-30T19:11:24Z",
  "aliases" : [ "CVE-2026-55219" ],
  "summary" : "Paymenter has race condition in payWithCredit() that enables credit double-spend",
  "details" : "### Summary\nThe credit payment implementation in `app/Livewire/Invoices/Show.php` executes a pessimistic row lock (`lockForUpdate()`) outside of an active database transaction. Because MySQL/MariaDB requires an enclosing transaction to enforce row-level locks, the guard is ineffective. Concurrent payment requests can exploit this race condition to read the same credit balance simultaneously, allowing users to pay multiple invoices using the same credit balance.\n\n### Technical Details\nThe issue occurs because the application attempts to lock the user's credit balance row in the database (`lockForUpdate()`) without opening a database transaction. In database systems like MySQL, a row lock only works inside a formal transaction; without one, the lock is completely ignored.\n\nBecause there is no active lock, two payment requests sent at the exact same millisecond can look at the database at the same time. Both requests see the original credit balance, decide it is sufficient, and approve the payment.\n\n### Impact\nThis race condition allows any authenticated user with a valid credit balance to bypass balance restrictions and settle multiple pending invoices simultaneously for the cost of a single invoice.\n\nBecause the payment processes successfully through ExtensionHelper::addPayment(), the application provisions the corresponding services or digital goods, resulting in direct financial or resource loss to the platform.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "paymenter/paymenter"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.5.5"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.5.4"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Paymenter/Paymenter/security/advisories/GHSA-pgcq-8grm-5rx9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Paymenter/Paymenter"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-30T19:11:24Z",
    "nvd_published_at" : null
  }
}