CVE-2026-49858
MediumCVSS 5.9Exploitation Probability (EPSS)
Low risk10th percentile — higher than 10% of all known CVEs
Summary
In API Platform Core versions from 2.6.0 prior to 4.1.29, 4.2.26, and 4.3.12, a missing isCacheKeySafe gate in the JSON:API and HAL item normalizers causes a cross-user attribute leak. The component cache (attributes, relationships, links) keyed on context cache key can be reused for a subsequent request from a different user with different permissions, exposing properties that should be hidden.
Risk Assessment
The organization is at risk of leaking sensitive API attribute data between users with different privilege levels. A lower-privileged user may see the structure of properties that the security predicate would otherwise have hidden for them.
Recommendation
Immediately update API Platform Core to version 4.1.29, 4.2.26, or 4.3.12 depending on the branch in use. After updating, verify that security rules for API attributes work correctly.
Original NVD description (English source)
API Platform Core is a system to create hypermedia-driven REST and GraphQL APIs. In versions from 2.6.0 prior to 4.1.29, 4.2.26, and 4.3.12, a missing isCacheKeySafe gate in the JSON:API and HAL item normalizers causes a cross-user attribute leak. #[ApiProperty(security: ...)] is evaluated per request to decide whether a property is exposed. The componentsCache arrays in ApiPlatform\JsonApi\Serializer\ItemNormalizer and ApiPlatform\Hal\Serializer\ItemNormalizer are keyed on $context['cache_key'], which is set unconditionally before delegating to the parent normalizer. The component structure (attributes, relationships, links) computed for one request can therefore be reused for a subsequent request whose user has a different set of accessible properties. A user with lower privileges may end up seeing the structure of properties that the security predicate would otherwise have hidden for them. This issue has been fixed in versions 4.1.29, 4.2.26, and 4.3.12.