Hoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve Actions (CVE-2026-50018) | HOL Guard CVE

Medium severityCVE-2026-50018GHSA-42J2-W334-QXW7

Hoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve Actions

Answer in brief

CVE-2026-50018 records a Medium severity vulnerability in Hoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve Actions. The current sources do not mark it as known exploited. The current feed maps SpectoLabs/hoverfly (generic), github.com/SpectoLabs/hoverfly (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 14, 2026Source checked Sep 17, 2026First seen by HOL Jul 15, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: Medium
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps SpectoLabs/hoverfly (generic), github.com/SpectoLabs/hoverfly (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
SpectoLabs/hoverflygeneric	< 1.12.8	Not reported
github.com/SpectoLabs/hoverflygo	<=1.12.7	1.12.8

Recommended response

Check inventory. Check lockfiles and deployed manifests for SpectoLabs/hoverfly, github.com/SpectoLabs/hoverfly.
Review the reported fix. Update github.com/SpectoLabs/hoverfly to 1.12.8 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 15, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.