CVE-2026-50013: high-severity vulnerability in SpectoLabs hoverfly
Hoverfly: Process Crash via Concurrent Map Write Race Condition in Diff Mode
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
SpectoLabs · hoverflyRelated CVEs — SpectoLabs hoverfly
In the same product, most dangerous first.
CVE-2024-45388HIGHArbitrary file read in the `/api/v2/simulation` endpoint in hoverfly (`GHSL-2023-274`)EPSS 55.6%CVE-2025-54123CRITICALHoverfly vulnerable to remote code execution at `/api/v2/hoverfly/middleware` endpoint due to insecure middleware implementationEPSS 10.9%CVE-2025-54376HIGHHoverfly's WebSocket endpoint `/api/v2/ws/logs` reachable without authentication even when --auth is enabled.EPSS 0.7%CVE-2026-50018MEDIUMHoverfly: Denial of Service via Goroutine Leak in Remote Post-Serve ActionsEPSS 0.5%