CVE-2026-49858
5.9 · MEDIUMOverview
CVE-2026-49858 is a medium-severity vulnerability. It was published on July 1, 2026 and has a CVSS 3.1 base score of 5.9 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.9, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
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.
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Frequently Asked Questions
What is CVE-2026-49858?
CVE-2026-49858 is a medium-severity vulnerability. It was published on July 1, 2026 and has a CVSS 3.1 base score of 5.9 (MEDIUM).
How severe is CVE-2026-49858?
This vulnerability has a CVSS 3.1 base score of 5.9, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-49858?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-49858?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-49858 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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