Hoverfly is an open source API simulation tool. Prior to version 1.12.8, remote post-serve actions use `http.DefaultClient` without any timeout configuration. When the remote endpoint is unreachable or intentionally slow (accepts TCP connection but never responds), each triggered proxy request spawns a goroutine that blocks indefinitely on `http.DefaultClient.Do()`. An attacker can cause unbounded goroutine accumulation leading to memory exhaustion and process crash (OOM kill). Unlike local post-serve action execution, this requires no binary execution, only a URL pointing to a non-responsive endpoint. Version 1.12.8 patches the issue.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-42j2-w334-qxw7 Hoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve Actions
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 15 Sep 2026 12:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 12 Sep 2026 18:45:00 +0000

Type Values Removed Values Added
First Time appeared Spectolabs
Spectolabs hoverfly
Vendors & Products Spectolabs
Spectolabs hoverfly

Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Description Hoverfly is an open source API simulation tool. Prior to version 1.12.8, remote post-serve actions use `http.DefaultClient` without any timeout configuration. When the remote endpoint is unreachable or intentionally slow (accepts TCP connection but never responds), each triggered proxy request spawns a goroutine that blocks indefinitely on `http.DefaultClient.Do()`. An attacker can cause unbounded goroutine accumulation leading to memory exhaustion and process crash (OOM kill). Unlike local post-serve action execution, this requires no binary execution, only a URL pointing to a non-responsive endpoint. Version 1.12.8 patches the issue.
Title Hoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve Actions
Weaknesses CWE-400
CWE-770
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-14T19:28:30.918Z

Reserved: 2026-06-02T22:46:02.579Z

Link: CVE-2026-50018

cve-icon Vulnrichment

Updated: 2026-09-14T19:28:04.891Z

cve-icon NVD

Status : Received

Published: 2026-09-11T22:16:37.950

Modified: 2026-09-14T20:16:44.783

Link: CVE-2026-50018

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T19:45:07Z

Weaknesses