CVE-2026-50018

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

MEDIUM
6.5
CVSS Score
Published: September 11, 2026 at 09:28 PM UTC
Updated: September 30, 2026 at 05:51 PM UTC
1 product affected across 1 vendorHoverfly

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.5%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.12.8
Affected range stops below 1.12.8, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-400CWE-770

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