VulnerabilityPublished 1 Jul 2026

CVE-2026-49858: api-platform core · Use of Cache Containing Sensitive Information

Affects api-platform coreSource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium · fixed in 4.3.8 : update api-platform core when convenient.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 3.1 base score

5.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.3.8, 4.2.25, 4.1.29 +2

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

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade core and api-platform/hal and api-platform/json-api to 4.3.8, 4.2.25 or 4.1.29; api-platform/core to 4.3.12, 4.2.26 or 4.1.29.

Affected software

Product	Affected	Fixed in
api-platformcore	Affected >=4.3.0 <4.3.8	Fixed in 4.3.8
api-platformcore	Affected >=4.2.0 <4.2.25	Fixed in 4.2.25
api-platformcore	Affected >=2.6.0 <4.1.29	Fixed in 4.1.29
api-platformapi-platform/hal	Affected >=4.3.0 <4.3.8	Fixed in 4.3.8
api-platformapi-platform/hal	Affected >=4.2.0 <4.2.25	Fixed in 4.2.25
api-platformapi-platform/hal	Affected >=2.6.0 <4.1.29	Fixed in 4.1.29

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in API Platform Core versions 4.1.29, 4.2.26, and 4.3.12. Users should upgrade to one of these versions or later to remediate the vulnerability. No alternative mitigations or temporary workarounds are indicated in the provided data.

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.

Impact

Confidentiality is impacted as users with lower privileges may gain unauthorized visibility into attributes and relationships that should be hidden according to security predicates. There is no impact on integrity or availability reported. The CVSS score of 5.9 (medium severity) reflects a network attack vector with high confidentiality impact but requiring high attack complexity and no privileges or user interaction.

Summary

The vulnerability in API Platform Core arises from the use of a cache keyed by $context['cache_key'] in the JSON:API and HAL item normalizers without verifying if the cache key is safe for reuse across different users. The #[ApiProperty(security: ...)] attribute is evaluated per request to control property exposure, but the cached component structure (attributes, relationships, links) can be reused for subsequent requests with different user privileges. This leads to a cross-user attribute leak where a user with lower privileges may see data structures meant to be restricted. The flaw is addressed in versions 4.1.29, 4.2.26, and 4.3.12.

CWE-524Use of Cache Containing Sensitive Information (opens in a new tab)
Base weakness
The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.
Architecture and Design
Protect information stored in cache.
Architecture and Design
Do not store unnecessarily sensitive information in the cache.
Architecture and Design
Consider using encryption in the cache.
OWASP ASVS 4.0.3
V8.1.1 (opens in a new tab)
V8.1.2 (opens in a new tab)
Attack patterns
Lifting Sensitive Data Embedded in Cache (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/api-platform/core/security/advisories/GHSA-pjhx-3c3w-9v23 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Jul 2026, 09:22 UTC

WeaknessesCWE-524, CWE-639

Technical details

References

Community reviews

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