CVE-2026-49858
API Platform Core: Cross-user attribute leak in JSON:API and HAL item normalizers due to missing isCacheKeySafe gate
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.
INFO
Published Date :
July 1, 2026, 8:17 p.m.
Last Modified :
July 2, 2026, 6:41 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update API Platform Core to 4.1.29 or later.
- Update API Platform Core to 4.2.26 or later.
- Update API Platform Core to 4.3.12 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-49858.
| URL | Resource |
|---|---|
| https://github.com/api-platform/core/security/advisories/GHSA-pjhx-3c3w-9v23 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-49858 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-49858
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-49858 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-49858 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 02, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-49858', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-02T12:19:58.405684Z'} -
New CVE Received by [email protected]
Jul. 01, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'api-platform', 'product': 'core', 'versions': [{'status': 'affected', 'version': '>= 2.6.0, < 4.1.29'}, {'status': 'affected', 'version': '>= 4.2.0, < 4.2.25'}, {'status': 'affected', 'version': '>= 4.3.0, < 4.3.8'}]}, {'vendor': 'api-platform', 'product': 'api-platform/hal', 'versions': [{'status': 'affected', 'version': '>= 2.6.0, < 4.1.29'}, {'status': 'affected', 'version': '>= 4.2.0, < 4.2.25'}, {'status': 'affected', 'version': '>= 4.3.0, < 4.3.8'}]}, {'vendor': 'api-platform', 'product': 'api-platform/json-api', 'versions': [{'status': 'affected', 'version': '>= 2.6.0, < 4.1.29'}, {'status': 'affected', 'version': '>= 4.2.0, < 4.2.25'}, {'status': 'affected', 'version': '>= 4.3.0, < 4.3.8'}]}] Added 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Added CWE CWE-524 Added CWE CWE-639 Added Reference https://github.com/api-platform/core/security/advisories/GHSA-pjhx-3c3w-9v23