Summary
@adonisjs/bodyparser has an incomplete fix for CVE-2026-25754
Full technical description
The fix for GHSA-f5x2-vj4h-vg4c / CVE-2026-25754 introduced in commit 40e1c71 is incomplete and can be bypassed through nested prototype pollution payloads.
The original patch replaced the internal FormFields storage object with Object.create(null), preventing direct payloads such as __proto__.polluted. However, payloads containing a non-dangerous segment before __proto__ or constructor.prototype, such as user.__proto__.polluted, still lead to Object.prototype pollution.
This issue is exploitable remotely through a single unauthenticated multipart/form-data request using the default configuration.
Affected versions
>= 10.1.3 < 10.1.5>= 11.0.0-next.9 < 11.0.3
Details
The regression tests added by the original fix only covered direct payloads such as:
__proto__.pollutedconstructor.prototype.polluted
These payloads are blocked because the root object no longer inherits from Object.prototype.
However, lodash _.set() (via @poppinss/utils) still creates intermediate objects using plain {} values. Once a normal segment is encountered, subsequent __proto__ or constructor.prototype segments regain access to Object.prototype.
References
- CWE-1321
- Prior advisory this bypasses: GHSA-f5x2-vj4h-vg4c / CVE-2026-25754
Impact
An unauthenticated attacker can remotely pollute Object.prototype on any route accepting multipart/form-data requests behind BodyParserMiddleware.
Because the pollution is process-wide, the impact may include authorization bypasses, unexpected behavior in downstream libraries, or prototype pollution gadget chains leading to remote code execution.
CVE-2026-48795 has a CVSS score of 8.6 (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 (10.1.5, 11.0.3); 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-2026-48795? CVE-2026-48795 is a high-severity security vulnerability in @adonisjs/bodyparser (npm), affecting versions >= 10.1.3, <= 10.1.4. It is fixed in 10.1.5, 11.0.3.
- How severe is CVE-2026-48795? CVE-2026-48795 has a CVSS score of 8.6 (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-2026-48795? @adonisjs/bodyparser (npm) versions >= 10.1.3, <= 10.1.4 is affected.
- Is there a fix for CVE-2026-48795? Yes. CVE-2026-48795 is fixed in 10.1.5, 11.0.3. Upgrade to this version or later.
- Is CVE-2026-48795 exploitable, and should I be worried? Whether CVE-2026-48795 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-2026-48795 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-2026-48795?
- Upgrade
@adonisjs/bodyparserto 10.1.5 or later - Upgrade
@adonisjs/bodyparserto 11.0.3 or later
- Upgrade