CVE-2026-55886

Jodit Editor is a WYSIWYG editor with written in pure TypeScript file and image editing capabilities. Versions prior to 4.12.26 are vulnerable to Prototype Pollution through Jodit.modules.Helpers.set(chain, value, obj), which 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. Applications that pass a user-controlled or partially user-controlled key path into Jodit.modules.Helpers.set() could be vulnerable, causing unexpected property injection, logic bypass, denial of service, or secondary security issues. This issue has been fixed in version 4.12.26.

Jodit Editor is a WYSIWYG editor with written in pure TypeScript file and image editing capabilities. Versions prior to 4.12.26 are vulnerable to Prototype Pollution through Jodit.modules.Helpers.set(chain, value, obj), which 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. Applications that pass a user-controlled or partially user-controlled key path into Jodit.modules.Helpers.set() could be vulnerable, causing unexpected property injection, logic bypass, denial of service, or secondary security issues. This issue has been fixed in version 4.12.26.

Summary

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;

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.

Patch

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.

Credit

Responsibly reported by Junming Wu.

Jodit Editor is a WYSIWYG editor with written in pure TypeScript file and image editing capabilities. Versions prior to 4.12.26 are vulnerable to Prototype Pollution through Jodit.modules.Helpers.set(chain, value, obj), which 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. Applications that pass a user-controlled or partially user-controlled key path into Jodit.modules.Helpers.set() could be vulnerable, causing unexpected property injection, logic bypass, denial of service, or secondary security issues. This issue has been fixed in version 4.12.26.

Jodit Editor is a WYSIWYG editor with written in pure TypeScript file and image editing capabilities. Versions prior to 4.12.26 are vulnerable to Prototype Pollution through Jodit.modules.Helpers.set(chain, value, obj), which 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. Applications that pass a user-controlled or partially user-controlled key path into Jodit.modules.Helpers.set() could be vulnerable, causing unexpected property injection, logic bypass, denial of service, or secondary security issues. This issue has been fixed in version 4.12.26.

Summary

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;

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.

Patch

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.

Credit

Responsibly reported by Junming Wu.