nimiq-blockchain: Peer-triggerable panic during history sync

Exploitation

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

CVSS

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

EPSS

• CVE-2026-34066: 0.24% estimated exploitation activity in the next 30 days; percentile 15.39 (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 HistoryStore::puthistorictxns uses an assert! to enforce invariants about HistoricTransaction.blocknumber (must be within the macro block being pushed and within the same epoch). During history sync, a peer can influence the history: &[HistoricTransaction] input passed into Blockchain::pushhistorysync, and a malformed history list can violate these invariants and trigger a panic. extendhistorysync calls this.historystore.addtohistory(..) before comparing the computed history root against the macro block header (block.historyroot()), so the panic can happen before later rejection checks run. Patches The patch for this vulnerability is included as part of v1.3.0. Workarounds No known workarounds.

Published by the source

22 Apr 2026, 19:23 UTC

Last modified by the source

27 Apr 2026, 16:22 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-j99g-7rqw-q9jg

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# Patch Next advisory brief: CVE-2026-34066

Advisory: nimiq-blockchain: Peer-triggerable panic during history sync
IDs: CVE-2026-34066, GHSA-j99g-7rqw-q9jg
Record: https://patchnext.com/advisories/cve-2026-34066 (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 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io nimiq-blockchain: affected <= 0.2.0

## Suggested inspection (read-only)
- crates.io nimiq-blockchain: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on nimiq-blockchain.
- 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-j99g-7rqw-q9jg (GitHub-reviewed advisory GHSA-j99g-7rqw-q9jg lists affected ranges: crates.io nimiq-blockchain >=0 <=0.2.0)

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