{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33993","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-24T22:20:06.212Z","datePublished":"2026-03-27T22:14:03.495Z","dateUpdated":"2026-03-30T15:45:18.660Z"},"containers":{"cna":{"title":"Locutus has Prototype Pollution via __proto__ Key Injection in unserialize()","problemTypes":[{"descriptions":[{"cweId":"CWE-1321","lang":"en","description":"CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/locutusjs/locutus/security/advisories/GHSA-4mph-v827-f877","tags":["x_refsource_CONFIRM"],"url":"https://github.com/locutusjs/locutus/security/advisories/GHSA-4mph-v827-f877"},{"name":"https://github.com/locutusjs/locutus/pull/597","tags":["x_refsource_MISC"],"url":"https://github.com/locutusjs/locutus/pull/597"},{"name":"https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4","tags":["x_refsource_MISC"],"url":"https://github.com/locutusjs/locutus/commit/345a6211e1e6f939f96a7090bfeff642c9fcf9e4"},{"name":"https://github.com/locutusjs/locutus/releases/tag/v3.0.25","tags":["x_refsource_MISC"],"url":"https://github.com/locutusjs/locutus/releases/tag/v3.0.25"}],"affected":[{"vendor":"locutusjs","product":"locutus","versions":[{"version":"< 3.0.25","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-27T22:14:03.495Z"},"descriptions":[{"lang":"en","value":"Locutus brings stdlibs of other programming languages to JavaScript for educational purposes. Prior to version 3.0.25, the `unserialize()` function in `locutus/php/var/unserialize` assigns deserialized keys to plain objects via bracket notation without filtering the `__proto__` key. When a PHP serialized payload contains `__proto__` as an array or object key, JavaScript's `__proto__` setter is invoked, replacing the deserialized object's prototype with attacker-controlled content. This enables property injection, for...in propagation of injected properties, and denial of service via built-in method override. This is distinct from the previously reported prototype pollution in `parse_str` (GHSA-f98m-q3hr-p5wq, GHSA-rxrv-835q-v5mh) — `unserialize` is a different function with no mitigation applied. Version 3.0.25 patches the issue."}],"source":{"advisory":"GHSA-4mph-v827-f877","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-30T15:45:05.433846Z","id":"CVE-2026-33993","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-30T15:45:18.660Z"}}]}}