CVE-2026-44483: RVF: Prototype pollution in @rvf/set-get reachable via @rvf/core preprocessFormData (HTTP form data)

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-26
Weakness: CWE-1321

Description

RVF (formerly Remix Validated Form) provides easy form validation and state management for React. From 6.0.0 to before 6.0.4 and 7.0.2, setPath in @rvf/set-get (used by @rvf/core to flatten incoming form data into a nested object) does not block the keys __proto__, constructor, or prototype when walking a path. Because field names in submitted form data are passed directly to setPath via preprocessFormData (and through parseFormData / validate), an attacker who can submit a form to a Remix / React Router app using the library can set arbitrary properties on Object.prototype of the running server process. This is a default-reachable prototype pollution primitive: no special configuration is required. Any endpoint that accepts a form via parseFormData or runs a validator created with createValidator is affected. This vulnerability is fixed in 6.0.4 and 7.0.2.

Affected products

airjp73 rvf: from 7.0.0, < 7.0.2; from 6.0.0, < 6.0.4
@rvf set-get: from 7.0.0, < 7.0.2; from 6.0.0, < 6.0.4

References

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