PatchTheCVECVE-2026-59952: Valibot helps validate data using a schema
40
This month
MEDIUM 6.9REMOTE
CVE-2026-59952 is a medium-severity flaw (CVSS 6.9) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Valibot helps validate data using a schema. Versions prior to 1.4.2 can throw a TypeError inside its flatten() helper when validation issues contain attacker-controlled object keys such as toString, valueOf, or hasOwnProperty. The issue is reachable through normal record() validation. record() intentionally filters __proto__, prototype, and constructor, but it still accepts other own keys that collide with inherited Object.prototype properties. I
Why this priority
- Remotely exploitable, no login, no user action
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.9 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.5% (top 56%) |
| CISA exploited list | No |
| Weakness | CWE-755 |
| Published | 2026-07-30 |
| Last modified | 2026-10-23 |
Publisher (CNA): GitHub, Inc.
Timeline
- Published CVE record published
- Updated Record last modified
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.