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CWE-524Weakness · CWE-524

CVE-2026-49858

MEDIUM · 5.9 CVSS v3.1 Published 2026-07-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The JSON:API and HAL item normalizers in API Platform Core cache component structures (attributes, relationships, links) using a cache key set unconditionally before delegating to the parent normalizer. This causes the cache to be shared across requests from different users, allowing a lower-privileged user to see property structures that should be hidden by the #[ApiProperty(security: ...)] predicate.

MitigationUpgrade API Platform Core to version 4.1.29, 4.2.26, or 4.3.12 or later to apply the isCacheKeySafe gate fix, then verify that security predicates correctly restrict property exposure across different user privilege levels.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify API Platform Core version
    Check your composer.json or installed packages for api-platform/core version. Run 'composer show api-platform/core' to see the installed version.
    Affected if The installed version is below 4.1.29, 4.2.26, or 4.3.12.
  2. Confirm JSON:API or HAL support is enabled
    Check your API Platform configuration (config/packages/api_platform.yaml or similar) for 'json:api: true' or 'hal: true' under the api_platform entry, or verify these formats are registered in your normalizer/encoder configuration.
    Affected if JSON:API or HAL formats are enabled in the API Platform configuration.
  3. Verify #[ApiProperty(security: ...)] predicates are in use
    Search your entity/DTO classes for the #[ApiProperty] attribute with a 'security' parameter, such as #[ApiProperty(security: 'is_granted("ROLE_ADMIN")')].
    Affected if Your API resources use #[ApiProperty(security: ...)] to restrict property access based on user privileges.
  4. Check if caching is enabled for the normalizers
    Inspect your cache configuration (such as Symfony cache pools or framework caching settings) to determine if caching is active for the API Platform normalizer layer.
    Affected if Caching is enabled and the application serves multiple users with different privilege levels.

You are affected if your API Platform Core version is below 4.1.29/4.2.26/4.3.12, you have JSON:API or HAL enabled, you use #[ApiProperty(security: ...)] predicates, and caching is active for requests from different privilege levels.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade API Platform Core to version 4.1.29, 4.2.26, or 4.3.12 or later to apply the isCacheKeySafe gate fix, then verify that security predicates correctly restrict property exposure across different user privilege levels.

Recommended fix High confidence

Upgrade to 4.1.29 (for 4.1.x), 4.2.26 (for 4.2.x), or 4.3.12 (for 4.3.x) depending on your current major version

  1. Check the current version of api-platform/core in your composer.json or composer.lock file
  2. Determine which major version line you are on (4.1.x, 4.2.x, or 4.3.x)
  3. Run 'composer require api-platform/core:^4.1.29' for 4.1.x users, 'composer require api-platform/core:^4.2.26' for 4.2.x users, or 'composer require api-platform/core:^4.3.12' for 4.3.x users
  4. Run 'composer update api-platform/core --with-all-dependencies' to apply the upgrade
  5. Verify the upgrade was successful by checking the installed version with 'composer show api-platform/core'
  6. Test that #[ApiProperty(security: ...)] correctly enforces security across different user privilege levels
  7. Clear any application caches (e.g., 'php bin/console cache:clear')
Caveat Review the CHANGELOG for your version line to check for any breaking changes between your current version and the target fixed version

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-49858 in production — separate from our analysis above.

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