KVStoreInterpreter::verify_signature_legacy answers true for every token and every key

Exploitation

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

CVSS

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

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

`KVStoreInterpreter::verify_signature_legacy(&PushDrop, &PublicKey)`, public and deprecated since 0.2.0 (the crate's first release), read neither argument and answered `true`. A KVStore token signed by nobody, a signed token checked against a key other than its controller's, and a PushDrop with no fields each passed. Its documentation said it delegated to the `KVStoreFields`-based verifier; it did not. An application that checks, with this function, a KVStore token it did not write (an overlay lookup's answer, or a transaction output a peer hands it) and acts on `true` accepts a value no controller signed, attributed to whatever controller the token names. No caller in the crate itself uses the function. This was run on 0.2.0, 0.5.0, 0.8.0, 0.8.7, 0.8.8, 0.9.0-beta.1 and 0.9.0-beta.7 as crates.io serves them, and the source of all 63 published versions carries the same constant body (the yanked 0.3.21 included). 0.8.9 answers `true` only for a token whose controller field is the…

Published by the source

13 Nov 2026, 12:00 UTC

Last modified by the source

13 Nov 2026, 12:45 UTC

Source last checked

14 Nov 2026, 08:25 UTC

1. Revision 1 · created · 14 Nov 2026

   Published from osv record RUSTSEC-2026-0529

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# Patch Next advisory brief: GHSA-mj2m-jxgv-r446

Advisory: KVStoreInterpreter::verify_signature_legacy answers true for every token and every key
IDs: GHSA-mj2m-jxgv-r446
Record: https://patchnext.com/advisories/rustsec-2026-0529 (revision 1, source checked 14 Nov 2026, 08:25 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: bsv-rs 0.9.0-beta.7.0, 0.8.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io bsv-rs: affected >= 0.0.0-0, < 0.8.9; >= 0.9.0-beta.1, < 0.9.0-beta.7.0; fixed in 0.9.0-beta.7.0, 0.8.9

## Suggested inspection (read-only)
- crates.io bsv-rs: 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 bsv-rs.
- 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://osv.dev/vulnerability/RUSTSEC-2026-0529 (OSV record RUSTSEC-2026-0529 lists affected ranges: crates.io bsv-rs >=0.0.0-0 =0.9.0-beta.1 <0.9.0-beta.7.0 (fixed))

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