Resource exhaustion in Spectolabs Hoverfly

CVE-2026-50018

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.

Vulnerability class: DoS (Denial of Service)

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-50018?
CVE-2026-50018 is a medium-severity vulnerability in Spectolabs Hoverfly, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-09-11.
How severe is CVE-2026-50018?
Medium severity. CVSS v3 base score is 6.5 out of 10.