Signature forgery in Biscuit

Exploitation

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

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2022-31053: 1.03% estimated exploitation activity in the next 30 days; percentile 63.66 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact The paper Cryptanalysis of Aggregate Γ-Signature and Practical Countermeasures in Application to Bitcoin defines a way to forge valid Γ-signatures, an algorithm that is used in the Biscuit specification version 1. It would allow an attacker to create a token with any access level. As Biscuit v1 was still an early version and not broadly deployed, we were able to contact all known users of Biscuit v1 and help them migrate to Biscuit v2. We are not aware of any active exploitation of this vulnerability. Patches The version 2 of the specification mandates a different algorithm than gamma signatures and as such is not affected by this vulnerability. The Biscuit implementations in Rust, Haskell, Go, Java and Javascript all have published versions following the v2 specification. Workarounds There is no known workaround, any use of Biscuit v1 should be migrated to v2. References Cryptanalysis of Aggregate Γ-Signature and Practical Countermeasures in Application to Bitcoin For more…

Published by the source

17 Jun 2022, 00:38 UTC

Last modified by the source

7 Mar 2023, 00:39 UTC

Source last checked

26 Oct 2026, 14:55 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-75rw-34q6-72cr

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# Patch Next advisory brief: CVE-2022-31053

Advisory: Signature forgery in Biscuit
IDs: CVE-2022-31053, GHSA-75rw-34q6-72cr
Record: https://patchnext.com/advisories/cve-2022-31053 (revision 1, source checked 26 Oct 2026, 14:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: biscuit-auth 2.0.0; github.com/biscuit-auth/biscuit-go 2.0.0; com.clever-cloud:biscuit-java 2.0.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io biscuit-auth: affected >= 1.0.0, < 2.0.0; fixed in 2.0.0
- Go github.com/biscuit-auth/biscuit-go: affected < 2.0.0; fixed in 2.0.0
- Maven com.clever-cloud:biscuit-java: affected < 2.0.0; fixed in 2.0.0

## Suggested inspection (read-only)
- crates.io biscuit-auth: check the installed version with your package manager.
- Go github.com/biscuit-auth/biscuit-go: check the installed version with your package manager.
- Maven com.clever-cloud:biscuit-java: 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 biscuit-auth, github.com/biscuit-auth/biscuit-go, com.clever-cloud:biscuit-java.
- 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-75rw-34q6-72cr (GitHub-reviewed advisory GHSA-75rw-34q6-72cr lists affected ranges: crates.io biscuit-auth >=1.0.0 =0 =0 <2.0.0)

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