6.5
MEDIUM CVSS 3.1
CVE-2026-50018
Hoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve Actions
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.

INFO

Published Date :

Sept. 11, 2026, 10:16 p.m.

Last Modified :

Sept. 11, 2026, 10:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-50018 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Hoverfly hoverfly
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Hoverfly to version 1.12.8 or later to resolve denial-of-service vulnerability.
  • Update Hoverfly to version 1.12.8 or later.
  • Configure timeouts for HTTP client requests.
  • Monitor resource utilization for potential DoS attacks.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-50018.

URL Resource
https://github.com/SpectoLabs/hoverfly/pull/1228
https://github.com/SpectoLabs/hoverfly/releases/tag/v1.12.8
https://github.com/SpectoLabs/hoverfly/security/advisories/GHSA-42j2-w334-qxw7
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-50018 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-50018 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-50018 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 11, 2026

    Action Type Old Value New Value
    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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
    Added CWE CWE-400
    Added CWE CWE-770
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/50xxx/CVE-2026-50018.json">CVE-2026-50018</a>
    Added Reference https://github.com/SpectoLabs/hoverfly/pull/1228
    Added Reference https://github.com/SpectoLabs/hoverfly/releases/tag/v1.12.8
    Added Reference https://github.com/SpectoLabs/hoverfly/security/advisories/GHSA-42j2-w334-qxw7
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.