rvf: Improperly Controlled Modification of Object Prototype Attributes
CVE-2026-44483 is a high-severity improperly controlled modification of object prototype attributes vulnerability in rvf from Airjp73, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected rvf versions: >= 7.0.0, < 7.0.2; >= 6.0.0, < 6.0.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of rvf you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Airjp73 | rvf | >= 7.0.0, < 7.0.2; >= 6.0.0, < 6.0.4 | Not stated |
| @rvf | set-get | >= 7.0.0, < 7.0.2; >= 6.0.0, < 6.0.4 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L. Scored by CNA (github.com).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improperly Controlled Modification of Object Prototype Attributes
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
How developers prevent this class of flaw
- By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
- By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
- When handling untrusted objects, validating using a schema can be used.
More Improperly Controlled Modification of Object Prototype Attributes vulnerabilities (CWE-1321)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Recent Improperly Controlled Modification of Object Prototype Attributes vulnerabilities
- 9.8 Critical severity
- 8.2 High severity
- 7.5 High severity
- 9.1 Critical severity
- 8.8 High severity
- 8.8 High severity
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