Vulnerability · Published Aug 14, 2025 · Assigned by GitHub_M

CVE-2025-55195@std/toml Prototype Pollution in Node.js and Browser

High 7.3

In plain English

A high-severity prototype pollution in std from denoland. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).

Severity (CVSS 3.1)7.3High

Exploit odds (30 days)0.4%top 69.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

@std/toml is the Deno Standard Library. Prior to version 1.0.9, an attacker can pollute the prototype chain in Node.js runtime and Browser when parsing untrusted TOML data, thus achieving Prototype Pollution (PP) vulnerability. This is because the library is merging an untrusted object with an empty object, which by default the empty object has the prototype chain. This issue has been patched in version 1.0.9.

Affected products (as reported)

Vendor	Product	Versions
denoland	std	< 1.0.9

Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

References

https://github.com/denoland/std/security/advisories/GHSA-crjp-8r9q-2j9r x_refsource_CONFIRM
https://github.com/denoland/std/commit/540662cfd6d71e969af292aa604ef4049dbe271b x_refsource_MISC
https://github.com/denoland/std/releases/tag/release-2025.08.13 x_refsource_MISC