{"id":"CVE-2025-58359","aliases":["EUVD-2025-26877","GHSA-wgq8-vr6r-mqxm"],"status":"published","title":"frost-core: refresh shares with smaller min_signers will reduce group security","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.","severity":{"version":"4.0","score":6,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00305,"percentile":0.23424,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-269","CWE-325"],"published":"2025-09-03T21:29:18Z","modified":"2026-10-28T02:31:14Z","fixes":[{"ecosystem":"crates.io","package":"frost-core","fixed_in":["2.2.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"frost-core","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.0.0"},{"fixed":"2.2.0"}]}]},{"source":"osv","ecosystem":"crates.io","package":"frost-core","ranges":[{"type":"SEMVER","events":[{"introduced":"2.0.0"},{"fixed":"2.2.0"}]}]}],"products":[{"vendor":"zcashfoundation","product":"frost"}],"references":[{"url":"https://github.com/ZcashFoundation/frost/security/advisories/GHSA-wgq8-vr6r-mqxm","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/ZcashFoundation/frost/commit/379ef689c733b3d9c80fd409071d4f3af4dafed2","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/ZcashFoundation/frost/releases/tag/frost-core%2Fv2.2.0","tags":["x_refsource_MISC","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-58359","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-wgq8-vr6r-mqxm"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/58xxx/CVE-2025-58359.json","tags":["advisory"]},{"url":"https://github.com/ZcashFoundation/frost","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2025-58359","title":"frost-core: refresh shares with smaller min_signers will reduce group security","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.","status":"published","published":"2025-09-04T23:50:45.746Z","modified":"2025-09-05T16:06:05.432Z","cvss":[{"version":"4.0","score":6,"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","level":"medium","assessor":"cna"}],"cwes":["CWE-325"],"updated_at":"2026-11-02T14:32:36.706507Z"}],"euvd":[{"id":"EUVD-2025-26877","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.","status":"published","published":"2025-09-04T23:50:45Z","modified":"2025-09-05T16:06:05Z","cvss":[{"version":"4.0","score":6,"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","level":"medium"}],"updated_at":"2026-11-02T20:31:46.9428Z"}],"ghsa":[{"id":"GHSA-wgq8-vr6r-mqxm","title":"frost-core: refresh shares with smaller min_signers will reduce security of group","description":"### Impact\n\nIt was not clear that it is not possible to change `min_signers` (i.e. the threshold) with the refresh share functionality (`frost_core::keys::refresh` module). 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; however, this could cause a security loss to the participant's shares. We have not determined the exact security implications of doing so and judged simpler to just validate `min_signers`. \n\n If for some reason you have done a refresh share procedure with a smaller `min_signers` we strongly recommend migrating to a new key. \n\n### Patches\n\nUpdating to 2.2.0 will ensure that the `min_signers` parameter will be validated. However it won't restore the security of groups refreshed with a smaller `min_signers` parameters.\n\n### Workarounds\n\nYou don't need to update if you don't use the refresh share functionality, or if you didn't try to change the `min_signers` parameter using the refresh share functionality.\n\n### References\n\nThank you [BlockSec](https://blocksec.com/) for reporting the finding","status":"published","published":"2025-09-03T21:29:18Z","modified":"2025-09-05T16:11:20Z","cvss":[{"version":"4.0","score":6,"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","level":"medium"}],"cwes":["CWE-269","CWE-325"],"updated_at":"2026-11-02T14:38:57.074217Z"}],"nvd":[{"id":"CVE-2025-58359","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.","status":"published","published":"2025-09-05T00:15:32.5Z","modified":"2026-06-17T09:44:21.51Z","cvss":[{"version":"4.0","score":6,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-325"],"updated_at":"2026-11-02T14:11:27.145738Z"}],"osv":[{"id":"CVE-2025-58359","title":"frost-core: refresh shares with smaller min_signers will reduce group security","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.","status":"published","published":"2025-09-04T23:50:45.746Z","modified":"2026-10-28T02:31:14.308725998Z","cvss":[{"version":"4.0","score":6,"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","level":"medium"}],"cwes":["CWE-325"],"updated_at":"2026-11-02T15:44:51.190588Z"},{"id":"GHSA-wgq8-vr6r-mqxm","title":"frost-core: refresh shares with smaller min_signers will reduce security of group","description":"### Impact\n\nIt was not clear that it is not possible to change `min_signers` (i.e. the threshold) with the refresh share functionality (`frost_core::keys::refresh` module). 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; however, this could cause a security loss to the participant's shares. We have not determined the exact security implications of doing so and judged simpler to just validate `min_signers`. \n\n If for some reason you have done a refresh share procedure with a smaller `min_signers` we strongly recommend migrating to a new key. \n\n### Patches\n\nUpdating to 2.2.0 will ensure that the `min_signers` parameter will be validated. However it won't restore the security of groups refreshed with a smaller `min_signers` parameters.\n\n### Workarounds\n\nYou don't need to update if you don't use the refresh share functionality, or if you didn't try to change the `min_signers` parameter using the refresh share functionality.\n\n### References\n\nThank you [BlockSec](https://blocksec.com/) for reporting the finding","status":"published","published":"2025-09-03T21:29:18Z","modified":"2025-09-05T16:11:20Z","cvss":[{"version":"4.0","score":6,"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","level":"medium"}],"cwes":["CWE-269","CWE-325"],"updated_at":"2026-11-02T15:46:58.767335Z"}]}}