CVE-2026-92599

joi: Quadratic regular-expression backtracking in Joi.string().isoDate()

Workarounds

None except capping the length of the string before it reaches joi.

Any application that validates a user-supplied string with Joi.string().isoDate() can be stalled by a single request. One of the regular expressions the rule runs over the input was unanchored, so a valid ISO date followed by a long run of fractional-second digits made the regex engine restart its search from every position in the string, costing time proportional to the square of the input length. 64 KB of digits costs about 1.4 s and 256 KB about 22 s.

A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use. Typical impact: denial of service when input is crafted to trigger backtracking.

CVE-2026-92599 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (17.13.7, 18.2.6); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Upgrade to version 17.13.7 or 18.2.6 depending on your current major version.

1. What is CVE-2026-92599? CVE-2026-92599 is a high-severity inefficient regular expression (ReDoS) vulnerability in joi (npm), affecting versions >= 17.2.0, < 17.13.7. It is fixed in 17.13.7, 18.2.6. A regular expression with worst-case exponential or polynomial matching time is applied to untrusted input, causing excessive CPU use.
2. How severe is CVE-2026-92599? CVE-2026-92599 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of joi are affected by CVE-2026-92599? joi (npm) versions >= 17.2.0, < 17.13.7 is affected.
4. Is there a fix for CVE-2026-92599? Yes. CVE-2026-92599 is fixed in 17.13.7, 18.2.6. Upgrade to this version or later.
5. Is CVE-2026-92599 exploitable, and should I be worried? Whether CVE-2026-92599 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-92599 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-92599?
   • Upgrade joi to 17.13.7 or later
   • Upgrade joi to 18.2.6 or later

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