CVE-2026-33993 | locutusjs locutus up to 3.0.24 unserialize prototype pollution

VDB-354058 · CVE-2026-33993 · GCVE-0-2026-33993 LOCUTUSJS LOCUTUS UP TO 3.0.24 UNSERIALIZE PROTOTYPE POLLUTION HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 5.1 $0-$5k 4.28- Summaryinfo A vulnerability described as problematic has been identified in locutusjs locutus up to 3.0.24. Affected by this issue is the function unserialize. Executing a manipulation can lead to prototype pollution. This vulnerability appears as CVE-2026-33993. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended. Detailsinfo A vulnerability was found in locutusjs locutus up to 3.0.24. It has been declared as problematic. This vulnerability affects the function unserialize. The manipulation with an unknown input leads to a prototype pollution vulnerability. The CWE definition for the vulnerability is CWE-1321. The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. As an impact it is known to affect integrity. CVE summarizes: 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. The advisory is available at github.com. This vulnerability was named CVE-2026-33993 since 03/24/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1059 by the MITRE ATT&CK project. Upgrading to version 3.0.25 eliminates this vulnerability. Productinfo Vendor locutusjs Name locutus Version 3.0.0 3.0.1 3.0.2 3.0.3 3.0.4 3.0.5 3.0.6 3.0.7 3.0.8 3.0.9 3.0.10 3.0.11 3.0.12 3.0.13 3.0.14 3.0.15 3.0.16 3.0.17 3.0.18 3.0.19 3.0.20 3.0.21 3.0.22 3.0.23 3.0.24 Website Product: https://github.com/locutusjs/locutus/ CPE 2.3info 🔒 🔒 🔒 CPE 2.2info 🔒 🔒 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CNA CVSS-B Score: 🔒 CNA CVSS-BT Score: 🔒 CNA Vector: 🔒 CVSSv3info VulDB Meta Base Score: 5.3 VulDB Meta Temp Score: 5.1 VulDB Base Score: 5.3 VulDB Temp Score: 5.1 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Prototype pollution CWE: CWE-1321 / CWE-94 / CWE-74 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Status: Not defined Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: locutus 3.0.25 Timelineinfo 03/24/2026 CVE reserved 03/27/2026 +3 days Advisory disclosed 03/27/2026 +0 days VulDB entry created 03/27/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: github.com Status: Confirmed CVE: CVE-2026-33993 (🔒) GCVE (CVE): GCVE-0-2026-33993 GCVE (VulDB): GCVE-100-354058 Entryinfo Created: 03/27/2026 23:53 Changes: 03/27/2026 23:53 (66) Complete: 🔍 Cache ID: 99:8C0:101 Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸