Cyber Posture

CVE-2026-44483

High
Microsoft: not affectedMSmacOS: not affectedMacLinux: not affectedLnxMobile: not affectedMobNetwork: not affectedNetApplication: not affectedAppOther: affectedOth

Published: 27 May 2026

Published
27 May 2026
Modified
27 May 2026
KEV Added
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Patch
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CVSS Score 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
EPSS Score 0.0004 13.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-44483 is a high-severity Prototype Pollution (CWE-1321) vulnerability. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190).
Threat & Defense Details

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
Why these techniques?

Direct prototype pollution in public-facing Remix/React Router form endpoints (parseFormData/createValidator) enables remote exploitation of the server process via crafted form submissions.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD 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…

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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.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
CWE-1321

EU & UK References

References