Description
Hoverfly is an open source API simulation tool. Prior to version 1.12.8, when Hoverfly is running in Diff mode, the `AddDiff()` function writes to the shared `responsesDiff` map without any synchronization (no mutex). When multiple proxy requests are processed concurrently (the normal case for any proxy), the concurrent map writes trigger Go's built-in race detector which causes a `fatal error: concurrent map read and map write`, immediately killing the entire Hoverfly process. This is trivially exploitable by sending multiple simultaneous requests. Version 1.12.8 patches the issue.
Published: 2026-09-11
Score: 7.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-qrh4-p6v4-mrfg Hoverfly: Process Crash via Concurrent Map Write Race Condition in Diff Mode
History

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, when Hoverfly is running in Diff mode, the `AddDiff()` function writes to the shared `responsesDiff` map without any synchronization (no mutex). When multiple proxy requests are processed concurrently (the normal case for any proxy), the concurrent map writes trigger Go's built-in race detector which causes a `fatal error: concurrent map read and map write`, immediately killing the entire Hoverfly process. This is trivially exploitable by sending multiple simultaneous requests. Version 1.12.8 patches the issue.
Title Hoverfly: Process Crash via Concurrent Map Write Race Condition in Diff Mode
Weaknesses CWE-362
CWE-820
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Subscriptions

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-09-11T21:27:40.296Z

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

Link: CVE-2026-50013

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T22:16:37.813

Modified: 2026-09-11T22:16:37.813

Link: CVE-2026-50013

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses
  • CWE-362

    Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

  • CWE-820

    Missing Synchronization