Zebra: Repeated Non-Finalized Shielded Transaction Aborts Zebra Before Duplicate-Nullifier Rejection

Exploitation

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

CVSS

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

EPSS

• CVE-2026-52739: 0.52% estimated exploitation activity in the next 30 days; percentile 43.95 (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.

Am I affected You are affected if: 1. You run zebrad up to and including v4.4.1. 2. Your node processes blocks past the checkpoint height (non-finalized state is active). 3. The network has NU5 or later activated. All default configurations are affected. Summary Chain::push in the non-finalized state updates the transaction-location index (txlocbyhash) before it runs the duplicate shielded-nullifier guard. When an invalid child block repeats a shielded transaction from its non-finalized parent, the asserteq!(priorpair, None, "transactions must be unique within a single chain") fires before the contextual validation that would cleanly reject the duplicate. Under Zebra's panic = "abort" release profile, this terminates the entire node process. The block should be rejected with a duplicate-nullifier contextual validation error. Instead, the ordering of index updates within Chain::push causes the process to abort. Details In zebra-state/src/service/nonfinalizedstate/chain.rs:1608-1628,…

Published by the source

2 Jul 2026, 19:46 UTC

Last modified by the source

2 Jul 2026, 19:46 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hhm7-qrv5-h4r6

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-52739

Advisory: Zebra: Repeated Non-Finalized Shielded Transaction Aborts Zebra Before Duplicate-Nullifier Rejection
IDs: CVE-2026-52739, GHSA-hhm7-qrv5-h4r6
Record: https://patchnext.com/advisories/cve-2026-52739 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: zebra-state 7.0.0; zebrad 4.5.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io zebra-state: affected <= 6.0.0; fixed in 7.0.0
- crates.io zebrad: affected <= 4.4.1; fixed in 4.5.0

## Suggested inspection (read-only)
- crates.io zebra-state: check the installed version with your package manager.
- crates.io zebrad: 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 zebra-state, zebrad.
- 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-hhm7-qrv5-h4r6 (GitHub-reviewed advisory GHSA-hhm7-qrv5-h4r6 lists affected ranges: crates.io zebra-state >=0 =0 <=4.4.1)

Commands are suggestions: review each one before running it.