CVE-2026-49858: API Platform Core: Cross-user attribute leak in JSON:API and HAL item normalizers due to missing isCacheKeySafe gate

DescriptionCVE.org

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.

• api-platform · core>= 2.6.0, < 4.1.29; >= 4.2.0, < 4.2.25; >= 4.3.0, < 4.3.8
• api-platform · api-platform/hal>= 2.6.0, < 4.1.29; >= 4.2.0, < 4.2.25; >= 4.3.0, < 4.3.8
• api-platform · api-platform/json-api>= 2.6.0, < 4.1.29; >= 4.2.0, < 4.2.25; >= 4.3.0, < 4.3.8

Exploitation

Unlikely (under 1%). EPSS under 1%, or no score yet.

CISA KEV

Not listed

Public check

No public nuclei template

Weakness

Use of Cache Containing Sensitive Information · Information Disclosure

Vendor

api-platform

Published

July 2026

Band

Unlikely (under 1%), July 2026

• NVD entrynvd.nist.gov
• CVE recordcve.org
• Weakness CWE-524cwe.mitre.org
• github.com/api-platform/core/security/advisories/GHSA-pjhx-3c3w-github.com