Summary
AdonisJS multipart body parsing has Prototype Pollution issue
Description
A Prototype Pollution vulnerability (CWE-1321) in AdonisJS multipart form-data parsing may allow a remote attacker to manipulate object prototypes at runtime. This impacts @adonisjs/bodyparser through version 10.1.2 and 11.x prerelease versions prior to 11.0.0-next.8. This issue has been patched in @adonisjs/bodyparser versions 10.1.3 and 11.0.0-next.9
Details
AdonisJS parses multipart/form-data requests via the BodyParser package. During multipart parsing, form field names are used to construct plain JavaScript objects representing the parsed request body.
Due to insufficient validation of multipart field names, specially crafted fields containing reserved property names such as __proto__, constructor, or prototype could be assigned directly to objects created during parsing. This allows an attacker to pollute object prototypes, potentially affecting other parts of the application that rely on these objects.
The vulnerability is limited to multipart request parsing and does not affect JSON or URL-encoded body parsing.
Impact
Exploitation requires an application endpoint that accepts and parses multipart/form-data requests.
If exploited, prototype pollution may lead to unexpected application behavior, logic bypasses, or security issues depending on how polluted objects are later consumed. The severity of the impact depends on application logic and usage patterns of the parsed request data.
CVE-2026-25754 has a CVSS score of 7.2 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (10.1.3, 11.0.0-next.9); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Fixes targeting v6 and v7 have been published below.
Users should upgrade to a version that includes the following fix:
Frequently Asked Questions
- What is CVE-2026-25754? CVE-2026-25754 is a high-severity security vulnerability in @adonisjs/bodyparser (npm), affecting versions <= 10.1.2. It is fixed in 10.1.3, 11.0.0-next.9.
- How severe is CVE-2026-25754? CVE-2026-25754 has a CVSS score of 7.2 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of @adonisjs/bodyparser are affected by CVE-2026-25754? @adonisjs/bodyparser (npm) versions <= 10.1.2 is affected.
- Is there a fix for CVE-2026-25754? Yes. CVE-2026-25754 is fixed in 10.1.3, 11.0.0-next.9. Upgrade to this version or later.
- Is CVE-2026-25754 exploitable, and should I be worried? Whether CVE-2026-25754 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-25754 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-25754?
- Upgrade
@adonisjs/bodyparserto 10.1.3 or later - Upgrade
@adonisjs/bodyparserto 11.0.0-next.9 or later
- Upgrade