CVE-2026-118772 joi: quadratic-time split in `string().email({ multiple: true })` allows denial of service
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-118772?
CVE-2026-118772 is a high-severity vulnerability in @hapi joi, published on 29 Oct 2026.
Official description
joi is a schema description language and data validator for JavaScript. From 17.1.1 until 17.13.9 and 18.3.1, the Joi.string().email({ multiple: true }) rule uses a separator regular expression whose leading whitespace quantifier is retried at every position in a long whitespace run that contains no separator, causing quadratic work during String.prototype.split. The behavior applies to the default separator and every custom separator. Applications that validate attacker-controlled values with the multiple option and no effective prior length limit can have the Node.js event loop blocked for seconds by one request, preventing other work. A .max() rule is not sufficient when abortEarly: false allows the email rule to run after the maximum-length check fails. This vulnerability is fixed in versions 17.13.9 and 18.3.1.
Weakness: CWE-1333
Which versions are affected by CVE-2026-118772?
How do I fix CVE-2026-118772?
No fix has been published for CVE-2026-118772 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-118772 being exploited?
There is no known exploitation of CVE-2026-118772 in the wild and no public exploit code.
Sources
Also known as GHSA-4528-x5fx-h6hg.