nimiq-keys: Unchecked Ed25519 signature length in TaggedPublicKey::verify causes remote node panic via DHT

CVE-2026-40092 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

A malicious network peer can crash any Nimiq full node by publishing a crafted Kademlia DHT record containing a TaggedSigned<ValidatorRecord, KeyPair> with a signature field whose byte length is not exactly 64. 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.

Patches

The patch for this vulnerability is formally released as part of v1.4.0.

Workarounds

No known workarounds.

Resources

See PR.

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2026-05-15 16:31:22 UTC
Updated
2026-06-08 20:14:56 UTC
GitHub reviewed
2026-05-15 16:31:22 UTC
NVD published
2026-05-20

EPSS Score

Score Percentile
0.03% 7.83%

CVSS Scores

Base score Version Severity Vector
7.5 3.1 —
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

Type Value
GHSA GHSA-27w2-87xv-37c6 ↗
CVE CVE-2026-40092 ↗

CWEs

CWE id Name
CWE-252 Unchecked Return Value

Credits

  • Piravlos (finder)

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
rust nimiq-keys <= 0.2.0 — —

References

cvelogic Threat Intelligence