VulnerabilityPublished 1 Jul 2026

CVE-2026-54164: api-platform core · Type Confusion

Affects api-platform coreSource CVE Database V5

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Not known to be exploited · CVSS 6.5 Medium · fixed in 4.3.12 : update api-platform core when convenient.

Data as of 12 Nov 2026, 23:24 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.3.12, 4.2.26, 4.1.30

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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/core to 4.3.12, 4.2.26 or 4.1.30.

Affected software

Product	Affected	Fixed in
api-platformcore	Affected >=4.3.0 <4.3.12	Fixed in 4.3.12
api-platformcore	Affected >=4.2.0 <4.2.26	Fixed in 4.2.26
api-platformcore	Affected <4.1.30	Fixed in 4.1.30
GitHubapi-platform/core`pkg:github/api-platform/core`Other threats	Affected <4.1.30 <4.2.26 <4.3.12	Fixed in 4.1.30 4.2.26 4.3.12

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AI-suggested

A fix is available in api-platform/core versions 4.1.30, 4.2.26, and 4.3.12 that adds a type guard to reject mismatched IRIs with a 400 Bad Request error. Users should upgrade to one of these patched versions to fully remediate the vulnerability. As a partial workaround, declaring explicit PHP types on all writable relation properties will cause Symfony's PropertyAccessor to reject mismatched types with an InvalidTypeException, but this does not cover collections of mixed-type interfaces. Older major versions 2.x and 3.x are end-of-life and have no planned fixes, so upgrading is strongly recommended.

Description

## Summary The API Platform serializer's `AbstractItemNormalizer` does not validate the resource type returned when resolving relation IRIs, allowing type confusion where a resource of an unintended type can be silently assigned to a relation property. ## Impact An attacker who can submit write requests (POST/PUT/PATCH) to an API Platform endpoint with writable relations can supply a relation IRI pointing to a resource of a different type than the relation's declared class. Because `getResourceFromIri()` does not pass an `$operation` to `IriConverter::getResourceFromIri()`, the `is_a` type guard at `IriConverter.php:86` is skipped. For untyped relation properties (legacy `@var`-only style), the wrong-typed object is silently assigned, corrupting invariants and potentially feeding downstream logic that assumes the declared type (CWE-843). For typed properties (modern PHP 8.x), the substitution is blocked by Symfony's PropertyAccessor with an `InvalidTypeException`. ## Affected versions - `api-platform/core` `< 4.1.30` - `api-platform/core` `>= 4.2.0, < 4.2.26` - `api-platform/core` `>= 4.3.0, < 4.3.12` ## Patched versions - `4.1.30` - `4.2.26` - `4.3.12` ## Fix An `is_a` guard is added inside `AbstractItemNormalizer::getResourceFromIri()` (and the equivalent inline call sites on 4.1) so that a mismatched IRI throws `InvalidArgumentException`, mirroring the operation-aware check the `IriConverter` already performs when an operation is supplied. This forces a `400 Bad Request` response for cross-type IRIs instead of a silent assignment. ## Workarounds Declare a PHP type on every writable relation property (e.g. `public ?Foo $relation = null;` instead of `@var Foo $relation`). Symfony's `PropertyAccessor` will then reject a mismatched object with `InvalidTypeException`. This does not cover collections of mixed-type interfaces; upgrading to a patched version is the only complete fix. ## Proof of concept A functional test posts a `Bar` IRI to a `Foo`-declared relation on an untyped property. Without the fix the server responds with `HTTP 201` and the Bar IRI appears in the response payload. With the fix the server responds with `HTTP 400` (`Invalid IRI "/bars/1"`). Full PoC: `tests/Functional/Security/TypeConfusionRelationIriTest.php` in the patched branches. ## References - `src/Serializer/AbstractItemNormalizer.php` — vulnerable relation IRI load - `src/Symfony/Routing/IriConverter.php` — conditional `is_a` guard (operation-aware path) ## Credit Reported by @alexandre-daubois.

Impact

An attacker with permission to submit write requests (POST/PUT/PATCH) to API Platform endpoints with writable relations can cause type confusion by assigning a resource of an unintended type to a relation property. This can silently corrupt application invariants and potentially cause incorrect behavior in downstream logic that assumes the declared type. The vulnerability does not impact confidentiality or availability directly but can lead to integrity issues. Typed properties in PHP 8.x mitigate the issue by throwing exceptions, but untyped properties remain vulnerable. There are no known exploits in the wild.

References

github.com/api-platform/core/security/advisories/GHSA-9rjg-x2p2-h68h (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Aug 2026, 15:38 UTC

WeaknessesCWE-843

Technical details

References

Community reviews

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