Answer in brief
CVE-2026-50013 records a High severity (CVSS 7.5) vulnerability in Hoverfly: Process Crash via Concurrent Map Write Race Condition in Diff Mode. The current sources do not mark it as known exploited. The current feed maps SpectoLabs/hoverfly (generic), github.com/SpectoLabs/hoverfly (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps SpectoLabs/hoverfly (generic), github.com/SpectoLabs/hoverfly (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| SpectoLabs/hoverflygeneric | <1.12.8 | 1.12.8 |
| github.com/SpectoLabs/hoverflygo | <=1.12.7 | 1.12.8 |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.