CVE-2026-118772
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AI Threat Summary
CVE-2026-118772 is a high-severity vulnerability with a CVSS score of 7.5 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
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.
Attack Chain
Attacker scans for vulnerable versions using version banners or PoC scanners
Attacker triggers CVE-2026-118772 vulnerability with a crafted request or payload
Vulnerability exploited to perform unauthorized actions on the target system
Depending on vulnerability type, attacker achieves data access, service disruption, or code execution
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-118772 |
| CVSS Score | 7.5 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Published | 2026-10-29 |
| Exploited | No |
| CISA KEV | No |
| PoC | Available |
References
- https://github.com/hapijs/joi/commit/03dc1d909818503b06240da…
- https://github.com/hapijs/joi/commit/807858d7480f5075b061081…
- https://github.com/hapijs/joi/pull/3162
- https://github.com/hapijs/joi/pull/3163
- https://github.com/hapijs/joi/releases/tag/v17.13.9
- https://github.com/hapijs/joi/releases/tag/v18.3.1
- https://github.com/hapijs/joi/security/advisories/GHSA-4528-…