How severe is CVE-2023-39967?

CVE-2023-39967 has a CVSS 3.x base score of 10.0, 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-2023-39967 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-39967?

CVE-2023-39967 affects Wiremock Studio. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-39967?

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-2023-39967 published?

CVE-2023-39967 was published on 2023-09-06 and last updated on 2026-06-17.

CVE-2023-39967

CVE-2023-39967 is a critical-severity vulnerability in Wiremock Studio with a CVSS 3.x base score of 10.0. 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-918.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-918
Affected product: Wiremock Studio
Published: 2023-09-06
Last modified: 2026-06-17

Description

WireMock is a tool for mocking HTTP services. When certain request URLs like “@127.0.0.1:1234" are used in WireMock Studio configuration fields, the request might be forwarded to an arbitrary service reachable from WireMock’s instance. There are 3 identified potential attack vectors: via “TestRequester” functionality, webhooks and the proxy mode. As we can control HTTP Method, HTTP Headers, HTTP Data, it allows sending requests with the default level of credentials for the WireMock instance. The vendor has discontinued the affected Wiremock studio product and there will be no fix. Users are advised to find alternatives.

Frequently asked questions

What is CVE-2023-39967?: WireMock is a tool for mocking HTTP services. When certain request URLs like “@127.0.0.1:1234" are used in WireMock Studio configuration fields, the request might be forwarded to an arbitrary service reachable from WireMock’s instance. There are 3 identified potential attack vectors: via “TestRequester” functionality, webhooks and the proxy mode. As we can control HTTP Method, HTTP Headers, HTTP Data, it allows sending requests with the default level of credentials for the WireMock instance. The vendor has discontinued the affected Wiremock studio product and there will be no fix. Users are advised to find alternatives.
How severe is CVE-2023-39967?: CVE-2023-39967 has a CVSS 3.x base score of 10.0, 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-2023-39967 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-39967?: CVE-2023-39967 affects Wiremock Studio. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-39967?: 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-2023-39967 published?: CVE-2023-39967 was published on 2023-09-06 and last updated on 2026-06-17.

References

https://github.com/wiremock/wiremock/security/advisories/GHSA-676j-xrv3-73vc

Affected products (1)

cpe:2.3:a:wiremock:studio:*:*:*:*:*:*:*:*

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