Summary
jodit: Prototype pollution in Jodit via Jodit.modules.Helpers.set()
Jodit.modules.Helpers.set(chain, value, obj) walks the dot-separated chain, creating and following each path segment, without filtering prototype-mutating keys. A chain that begins with (or contains) __proto__, constructor, or prototype lets the final assignment reach and mutate Object.prototype (prototype pollution).
Affected
- Package:
jodit(npm) - Versions:
< 4.12.26 - Public API:
Jodit.modules.Helpers.set(chain, value, obj)
Proof of Concept
const { Jodit } = require('jodit');
delete Object.prototype.polluted;
Jodit.modules.Helpers.set('__proto__.polluted', 'yes', {});
console.log(({}).polluted); // "yes" (before the fix)
delete Object.prototype.polluted;
Credit
Responsibly reported by Junming Wu.
Impact
Applications that pass a user-controlled or partially user-controlled key path into Jodit.modules.Helpers.set() could be vulnerable to prototype pollution (CWE-1321): unexpected property injection, logic bypass, denial of service, or secondary security issues.
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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See it in your environmentNew to Kodem? Get a demo →Remediation advice
Fixed in 4.12.26 by rejecting any chain whose segments include __proto__, constructor, or prototype, reusing the same guard introduced for Jodit.configure() in 4.12.18.
Frequently Asked Questions
- What is CVE-2026-55886? CVE-2026-55886 is a medium-severity security vulnerability in jodit (npm), affecting versions < 4.12.26. It is fixed in 4.12.26.
- Which versions of jodit are affected by CVE-2026-55886? jodit (npm) versions < 4.12.26 is affected.
- Is there a fix for CVE-2026-55886? Yes. CVE-2026-55886 is fixed in 4.12.26. Upgrade to this version or later.
- Is CVE-2026-55886 exploitable, and should I be worried? Whether CVE-2026-55886 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-2026-55886 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-2026-55886? Upgrade
joditto 4.12.26 or later.