Improper input validation in Nimiq Nimiq-Blockchain
CVE-2026-34066
nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. Prior to version 1.3.0, `HistoryStore::put_historic_txns` uses an `assert!` to enforce invariants about `HistoricTransaction.block_number` (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::push_history_sync`, and a malformed history list can violate these invariants and trigger a panic. `extend_history_sync` calls `this.history_store.add_to_history(..)` before comparing the computed history root against the macro block header (`block.history_root()`), so the panic can happen before later rejection checks run. The patch for this vulnerability is included as part of v1.3.0. No known workarounds are available.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.002 (15.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H.
Affected products
- Nimiq Nimiq-blockchain — versions < 1.3.0
- Nimiq Nimiq_proof-of-stake
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-34066?
- CVE-2026-34066 is a medium-severity vulnerability in Nimiq Nimiq-Blockchain, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2026-04-22.
- How severe is CVE-2026-34066?
- Medium severity. CVSS v3 base score is 5.3 out of 10.