Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/SpectoLabs/hoverfly/pull/1227
- https://github.com/SpectoLabs/hoverfly/releases/tag/v1.12.8
- https://github.com/SpectoLabs/hoverfly/security/advisories/GHSA-qrh4-p6v4-mrfg
FAQ
What is CVE-2026-50013?
CVE-2026-50013 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 synchroniz...
How severe is CVE-2026-50013?
CVE-2026-50013 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-50013?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.