How severe is GHSA-7xfq-xh6v-4mrm?

GHSA-7xfq-xh6v-4mrm has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-7xfq-xh6v-4mrm?

GHSA-7xfq-xh6v-4mrm affects the following packages: json-serializer (npm). Ecosystems affected: npm.

How do I fix GHSA-7xfq-xh6v-4mrm?

Update json-serializer to 2.0.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7xfq-xh6v-4mrm is resolved across your whole dependency graph.

How do I detect GHSA-7xfq-xh6v-4mrm in my npm dependencies?

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

How do I mitigate GHSA-7xfq-xh6v-4mrm if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-7xfq-xh6v-4mrm actively exploited in the wild?

No public exploit code has been indexed for GHSA-7xfq-xh6v-4mrm 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.

When was GHSA-7xfq-xh6v-4mrm published, and has it been updated?

GHSA-7xfq-xh6v-4mrm was published on September 1, 2020 and was last updated on October 1, 2021. 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

CRITICAL severity

Malicious Package in json-serializerGHSA-7xfq-xh6v-4mrm

CRITICAL

GHSA-7xfq-xh6v-4mrm is a critical-severity (CVSS 9.8) vulnerability in json-serializer. A fix is available for json-serializer — see the affected versions and patch details below.

Published

Sep 1, 2020

Updated

Oct 1, 2021

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 1, 2021 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

📦json-serializer

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Version 2.0.10 of json-serializer contained malicious code. The code when executed in the browser would enumerate password, cvc, cardnumber fields from forms and send the extracted values to https://js-metrics.com/minjs.php?pl=

Recommendation

If version 2.0.10 of this module is found installed you will want to replace it with a version before or after 2.0.10. In addition to replacing the installed module, you will also want to evaluate your application to determine whether or not user data was compromised.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`json-serializer`	≥ 2.0.10&&< 2.0.11	2.0.11`npm install json-serializer@2.0.11`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for json-serializer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update json-serializer to 2.0.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7xfq-xh6v-4mrm is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

Version 2.0.10 of `json-serializer` contained malicious code. The code when executed in the browser would enumerate password, cvc, cardnumber fields from forms and send the extracted values to `https://js-metrics.com/minjs.php?pl=` ## Recommendation If version 2.0.10 of this module is found installed you will want to replace it with a version before or after 2.0.10. In addition to replacing the installed module, you will also want to evaluate your application to determine whether or not user data was compromised.

O3 Security · Impact-Aware SCA

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