Hoverfly: Process Crash via Concurrent Map Write Race Condition in Diff Mode

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-50013
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-11 22:16:37 UTC
Updated2026-09-11 22:16:37 UTC
DescriptionHoverfly 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-362 | CWE-820 | CWE-362 CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') | CWE-820 CWE-820: Missing Synchronization

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA SpectoLabs Hoverfly affected < 1.12.8 Not specified

References

ReferenceSourceLinkTags
github.com/SpectoLabs/hoverfly/pull/1227 [email protected] github.com
github.com/SpectoLabs/hoverfly/releases/tag/v1.12.8 [email protected] github.com
github.com/SpectoLabs/hoverfly/security/advisories/GHSA-qrh4-p6v4-mrfg [email protected] github.com
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