Inefficient Algorithmic Complexity Affecting webonyx/graphql-php package, versions <15.31.5
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PHP-WEBONYXGRAPHQLPHP-16066599
- published15 Apr 2026
- disclosed14 Apr 2026
- creditAshwak N
Introduced: 14 Apr 2026
CVE-2026-40476 (opens in a new tab)How to fix?
Upgrade webonyx/graphql-php to version 15.31.5 or higher.
Overview
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity through the OverlappingFieldsCanBeMerged validation process. An attacker can cause excessive CPU usage and resource exhaustion by submitting queries containing thousands of repeated fields with the same response name, leading to significant delays or timeouts during validation.