How severe is CVE-2018-6342?

CVE-2018-6342 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-6342 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-6342?

CVE-2018-6342 affects Facebook React-dev-utils. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2018-6342?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2018-6342 published?

CVE-2018-6342 was published on 2018-12-31 and last updated on 2026-06-17.

CVE-2018-6342

CVE-2018-6342 is a critical-severity vulnerability in Facebook React-dev-utils with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Facebook React-dev-utils
Published: 2018-12-31
Last modified: 2026-06-17

Description

react-dev-utils on Windows allows developers to run a local webserver for accepting various commands, including a command to launch an editor. The input to that command was not properly sanitized, allowing an attacker who can make a network request to the server (either via CSRF or by direct request) to execute arbitrary commands on the targeted system. This issue affects multiple branches: 1.x.x prior to 1.0.4, 2.x.x prior to 2.0.2, 3.x.x prior to 3.1.2, 4.x.x prior to 4.2.2, and 5.x.x prior to 5.0.2.

Frequently asked questions

What is CVE-2018-6342?: react-dev-utils on Windows allows developers to run a local webserver for accepting various commands, including a command to launch an editor. The input to that command was not properly sanitized, allowing an attacker who can make a network request to the server (either via CSRF or by direct request) to execute arbitrary commands on the targeted system. This issue affects multiple branches: 1.x.x prior to 1.0.4, 2.x.x prior to 2.0.2, 3.x.x prior to 3.1.2, 4.x.x prior to 4.2.2, and 5.x.x prior to 5.0.2.
How severe is CVE-2018-6342?: CVE-2018-6342 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-6342 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-6342?: CVE-2018-6342 affects Facebook React-dev-utils. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2018-6342?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2018-6342 published?: CVE-2018-6342 was published on 2018-12-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:facebook:react-dev-utils:*:*:*:*:*:*:*:*

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