How severe is GHSA-65fc-cr5f-v7r2?

No CVSS score has been assigned to GHSA-65fc-cr5f-v7r2 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-65fc-cr5f-v7r2?

GHSA-65fc-cr5f-v7r2 affects the following packages: js-toml (npm). Ecosystems affected: npm.

How do I fix GHSA-65fc-cr5f-v7r2?

Update js-toml to 1.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-65fc-cr5f-v7r2 is resolved across your whole dependency graph.

How do I detect GHSA-65fc-cr5f-v7r2 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for js-toml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-65fc-cr5f-v7r2 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is GHSA-65fc-cr5f-v7r2 actively exploited in the wild?

No public exploit code has been indexed for GHSA-65fc-cr5f-v7r2 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-65fc-cr5f-v7r2?

GHSA-65fc-cr5f-v7r2 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 47th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-65fc-cr5f-v7r2?

GHSA-65fc-cr5f-v7r2 is classified as CWE-1321 (CWE-1321). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-65fc-cr5f-v7r2 published, and has it been updated?

GHSA-65fc-cr5f-v7r2 was published on August 4, 2025 and was last updated on August 5, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

js-toml Prototype Pollution VulnerabilityGHSA-65fc-cr5f-v7r2

Fix: sunnyadn/js-toml@b125910

GHSA-65fc-cr5f-v7r2 is a CWE-1321 vulnerability in js-toml. A fix is available for js-toml — see the affected versions and patch details below.

Also known asCVE-2025-54803

Published

Aug 4, 2025

Updated

Aug 5, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for GHSA-65fc-cr5f-v7r2.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk+0.04%

Lower risk than most CVEs47th percentile — riskier than 47% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

34other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

js-tomlnpm

36Kdownloads / week

Description

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

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`js-toml`	all versions	1.0.2`npm install js-toml@1.0.2`

Affected Products

1 product · 1 configurations

Application

js-tomlsunnyadn

< 1.0.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for js-toml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update js-toml to 1.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-65fc-cr5f-v7r2 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

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 consumi

O3 Security · Impact-Aware SCA

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