Blst vulnerable to incorrect results for some inputs in blst_fp_eucl_inverse function

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact Blst versions v0.3.0 to v0.3.2 can produce the incorrect outputs for some inputs to the blstfpeuclinverse function. This could theoretically result in the creation of an invalid signature from correct inputs. However, fuzzing of higher level functions such as sign and verify were unable to produce incorrect results and there has been no reported occurrences of this issue being encountered in production use. Description During the course of differential fuzzing of the blst library by @guidovranken it was discovered that blst would produce the incorrect result for some input values in the inverse function. This was the result of the introduction of a new inversion formula in version v0.3.0. This source of these incorrect outputs was due to two issues: 1. The amount of inner loop iterations was not sufficient for the algorithm to converge. 2. It was erroneously assumed that the absolute value of the intermediate result would be capped at 767-bits. As a result, some output values…

Published by the source

7 Oct 2022, 07:25 UTC

Last modified by the source

20 May 2024, 21:31 UTC

Source last checked

26 Oct 2026, 15:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x279-68rr-jp4p

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# Patch Next advisory brief: GHSA-x279-68rr-jp4p

Advisory: Blst vulnerable to incorrect results for some inputs in blst_fp_eucl_inverse function
IDs: GHSA-x279-68rr-jp4p
Record: https://patchnext.com/advisories/ghsa-x279-68rr-jp4p (revision 1, source checked 26 Oct 2026, 15:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/supranational/blst 0.3.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/supranational/blst: affected >= 0.3.0, < 0.3.3; fixed in 0.3.3

## Suggested inspection (read-only)
- Go github.com/supranational/blst: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/supranational/blst.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x279-68rr-jp4p (GitHub-reviewed advisory GHSA-x279-68rr-jp4p lists affected ranges: Go github.com/supranational/blst >=0.3.0 <0.3.3)

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