Bsv rs: Shamir backup recovery accepts a share at x = 0, so a supplied share can substitute the recovered private key
Affects bsv-rsSource GCVE Database
CVSS 9.1 Critical : upgrade to 0.9.0-beta.7.0 or 0.8.7 as a priority.
Data as of 12 Nov 2026, 08:06 UTC
- Patch
- Available – fixed in 0.9.0-beta.7.0, 0.8.7
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NWhat to do
Upgrade bsv-rs to 0.9.0-beta.7.0 or 0.8.7.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
crates.iobsv-rspkg:cargo/bsv-rsOther threats | Affected
| Fixed in
|
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AI-suggested
Upgrade to bsv-rs version 0.8.7 or later (including 0.9.0-beta.7.0 or later) where the acceptance of shares with x=0 is refused before interpolation. If upgrading is not possible, implement a manual check before recovery: split each share on '.' into four fields, base58-decode the x field, and reject the set if the x value decodes to zero (including the one-character field '1' or values at or above the field prime) or if duplicate x values exist in the set.
Description
The bsv-rs crate's Shamir backup recovery mechanism accepted shares with an x coordinate of 0, allowing an attacker to supply a crafted share that directly determines the recovered private key. This flaw existed since the crate's first release (0.2.0) and was fixed in versions 0.8.7 and 0.9.0-beta.7.0. The vulnerability allows an attacker to substitute the recovered private key if the application recovers a Shamir backup from shares it did not originally produce.