CVE-2026-118772
joi: quadratic-time split in `string().email({ multiple: true })` allows denial of service
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | joi | >= 17.1.1, < 17.13.9 | 17.13.9 |
| npm | @hapi/joi | >= 16.0.0, <= 17.1.1 | none recorded |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Hapijs | Joi | from 18.0.0, before 18.3.1 Version 16.0.0, ≤ 17.1.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-4528-x5fx-h6hg
- https://github.com/hapijs/joi/security/advisories/GHSA-4528-x5fx-h6hg
- https://nvd.nist.gov/vuln/detail/CVE-2026-118772
- https://github.com/hapijs/joi/pull/3162
- https://github.com/hapijs/joi/pull/3163
- https://github.com/hapijs/joi/commit/03dc1d909818503b06240dadc81e9227ed2649cf
- https://github.com/hapijs/joi/commit/807858d7480f5075b0610817e3e44230890fb18e
- https://github.com/hapijs/joi/releases/tag/v17.13.9
- https://github.com/hapijs/joi/releases/tag/v18.3.1