CVE-2025-54803: js-toml Prototype Pollution

Description

js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. In versions below 1.0.2, 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. This is fixed in version 1.0.2.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Weakness Type (CWE)

CWE-1321 CWE-1321

Affected Products

Vendor	Product	Versions
sunnyadn	js-toml	< 1.0.2

References

Advisories & Patches

https://github.com/sunnyadn/js-toml/commit/b125910a3f094b744c9c3571360d4b9e3a472f66 https://github.com/sunnyadn/js-toml/security/advisories/GHSA-65fc-cr5f-v7r2

Exploits

https://gist.github.com/siunam321/f3dc4d21a5a932c67b6c11d0026f5afc https://gist.github.com/siunam321/f3dc4d21a5a932c67b6c11d0026f5afc

Frequently Asked Questions

What is CVE-2025-54803? +

js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. In versions below 1.0.2, 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. This is fixed in version 1.0.2. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-54803? +

CVE-2025-54803 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-54803? +

CVE-2025-54803 affects products from sunnyadn, specifically: js-toml. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-54803? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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