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

@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.

Published: 2025-08-14 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-55195 is rated Moderate Risk (42.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.16%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-55195

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-30 0.06% 0.16% +0.10%
2 2025-08-20 0.04% 0.06% +0.01%
3 2025-08-15 0.04%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-55195

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 3.4 [email protected]

Weakness enumeration for CVE-2025-55195

Affected software / configurations for CVE-2025-55195

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-55195

cvelogic Threat Intelligence