GHSA-65fc-cr5f-v7r2

Source

https://github.com/advisories/GHSA-65fc-cr5f-v7r2

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/08/GHSA-65fc-cr5f-v7r2/GHSA-65fc-cr5f-v7r2.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-65fc-cr5f-v7r2

Aliases

CVE-2025-54803

Published

2025-08-04T16:07:05Z

Modified

2025-08-05T17:11:05Z

Severity

7.9 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H CVSS Calculator

Summary

js-toml Prototype Pollution Vulnerability

Details

A prototype pollution vulnerability in js-toml allows a remote attacker to add or modify properties of the global Object.prototype by parsing a maliciously crafted TOML input.

Impact

The js-toml library is vulnerable to Prototype Pollution. When parsing a TOML string containing the specially crafted key __proto__, an attacker can add or modify properties on the global Object.prototype.

While the js-toml library itself does not contain known vulnerable "gadgets", this can lead to severe security vulnerabilities in applications that use the library. For example, if the consuming application checks for the existence of a property for authorization purposes (e.g., user.isAdmin), this vulnerability could be escalated to an authentication bypass. Other potential impacts in the application include Denial of Service (DoS) or, in some cases, Remote Code Execution (RCE), depending on the application's logic and dependencies.

Any application that uses an affected version of js-toml to parse untrusted input is vulnerable. The severity of the impact, ranging from unexpected behavior to a full security compromise, is dependent on the application's specific code and its handling of object properties.

Patches

This vulnerability has been patched in version 1.0.2.

All users are advised to upgrade to version 1.0.2 or later to mitigate this issue. Users of all prior versions are affected.

Workarounds

If you are unable to upgrade to a patched version, the only mitigation is to ensure that any TOML input being passed to the js-toml library is from a fully trusted source and has been validated to not contain malicious keys.

References

This vulnerability was discovered and responsibly disclosed by siunam.
The Proof-of-Concept can be found at this Gist: https://gist.github.com/siunam321/f3dc4d21a5a932c67b6c11d0026f5afc
For more information on Prototype Pollution, see PortSwigger's explanation: https://portswigger.net/web-security/prototype-pollution

Database specific

{
    "cwe_ids": [
        "CWE-1321"
    ],
    "nvd_published_at": "2025-08-05T01:15:42Z",
    "severity": "HIGH",
    "github_reviewed": true,
    "github_reviewed_at": "2025-08-04T16:07:05Z"
}

References

Affected packages

npm / js-toml

Package

Name: js-toml; View open source insights on deps.dev
Purl: pkg:npm/js-toml

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

1.0.2