CVE-2026-33993— Locutus has Prototype Pollution via __proto__ Key Injection in unserialize()
Quick assessment
Affected
locutusjs locutus
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Locutus是Locutus开源的一个JavaScript代码库。 Locutus 3.0.25之前版本存在安全漏洞，该漏洞源于unserialize函数未过滤__proto__键，可能导致原型污染、属性注入和拒绝服务攻击。
Possible ATT&CK Techniques 1 AI
T1190 · Exploit Public-Facing Application
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-33993
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Locutus has Prototype Pollution via __proto__ Key Injection in unserialize()
Source: CVE Program / CVE List V5
Vulnerability Description
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: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
CWE-1321
Source: CVE Program / CVE List V5
Vulnerability Title
Locutus 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Locutus是Locutus开源的一个JavaScript代码库。 Locutus 3.0.25之前版本存在安全漏洞，该漏洞源于unserialize函数未过滤__proto__键，可能导致原型污染、属性注入和拒绝服务攻击。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2026-33993
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-33993
请登录查看更多情报信息。
Patches & Fixes for CVE-2026-33993 (2)
Vendor Advisories for CVE-2026-33993 (1)
Vendor Pages for CVE-2026-33993 (1)
-
Release v3.0.25 · locutusjs/locutus · GitHub x_refsource_MISC
IV. Related Vulnerabilities
Same product: locutus
-
CVE-2026-33994
Locutus Prototype Pollution due to incomplete fix for CVE-20 -
CVE-2026-32304
Locutus: RCE via unsanitized input in create_function() -
CVE-2026-29091
Locutus: Remote Code Execution (RCE) in locutus call_user_fu -
CVE-2026-25521
Locutus is vulnerable to Prototype Pollution -
CVE-2021-23392
Regular Expression Denial of Service (ReDoS)
Same vendor: locutusjs
Same weakness: CWE-1321
-
CVE-2026-104848
Tinypool: Prototype Pollution gadget in worker options leads -
CVE-2026-86536
Apache Thrift, Apache Thrift, Apache Thrift: A map key from -
CVE-2026-104183
stream-json: Prototype pollution: Assembler writes this.curr -
CVE-2026-102992
piscina: Prototype-pollution gadget in ThreadPool.options al -
CVE-2026-91860
Prototype Pollution in Vaadin Charts and Component Base via
V. Comments for CVE-2026-33993
No comments yet