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VulnerabilityPublished

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

0

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

CVSS 3.1 base score
9.1Critical
How severe the flaw is on the 0–10 CVSS scale.
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:N

What to do

Upgrade bsv-rs to 0.9.0-beta.7.0 or 0.8.7.

Affected software

ProductAffectedFixed in
crates.iobsv-rspkg:cargo/bsv-rsOther threatsAffected
  • >=0.0.0-0 <0.8.7
  • >=0.9.0-beta.1 <0.9.0-beta.7.0
Fixed in
  • 0.8.7
  • 0.9.0-beta.7.0

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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.

References

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