# CVE-2026-40092

## Summary

- **CVE ID:** CVE-2026-40092
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-252
- **Published:** May 20, 2026
- **Last Modified:** May 21, 2026

## Description

nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. In versions 1.3.0 and below, a malicious network peer can crash any Nimiq full node by publishing a crafted Kademlia DHT record. The maliciously crafted record would contain a TaggedSigned<ValidatorRecord, KeyPair> with a signature field whose byte length is not exactly 64 in order to cause a crash. When the victim node's DHT verifier calls TaggedSigned::verify, execution reaches Ed25519Signature::from_bytes(sig).unwrap() in the TaggedPublicKey implementation for Ed25519PublicKey. The from_bytes call fails because ed25519_zebra::Signature::try_from rejects slices not 64 bytes, and the unwrap() panics. The BLS TaggedPublicKey implementation correctly returns false on error; only the Ed25519 implementation panics. This issue has been fixed in version 1.4.0.

## Affected Products

- nimiq — core-rs-albatross (< 1.4.0)

## References

- [CNA](https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-27w2-87xv-37c6)
- [CNA](https://github.com/nimiq/core-rs-albatross/pull/3708)
- [CNA](https://github.com/nimiq/core-rs-albatross/commit/807ee8e99a7ccdc604d49971f292854bfa36754d)
- [CNA](https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.63%
- **EPSS Percentile:** 48.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._