jodit: Prototype pollution in Jodit via Jodit.modules.Helpers.set()

### 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 ```js 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.

Source published

18 Jun 2026 13:05:01 UTC

Source modified

31 Jul 2026 14:45:18 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N

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