VulnerabilityDeferred

CVE-2025-55195

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.

HIGH 7.3EPSS 0.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1: 7.3 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS: 0.33% probability · 26th percentile
CISA KEV: Not listed
Weakness: CWE-1321
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.