CVE-2026-40092: nimiq-keys Unchecked Ed25519 Signature Length Vulnerability

HIGH
Advisory Identifier: GHSA-27w2-87xv-37c6
Share
CVSS 7.5
CWE-252
Published
Advisory Summary

CVE-2026-40092 is a HIGH (CVSS 7.5) unchecked ed25519 signature length vulnerability (CWE-252: Unchecked Return Value) affecting nimiq-keys libraries in the crates.io ecosystem. The issue involves unchecked ed25519 signature length in taggedpublickey::verify causes remote node panic via dht. Remediation is available in the latest vendor maintenance releases.

CVE-2026-40092 at a Glance

CVE Identifier CVE-2026-40092
GHSA Identifier GHSA-27w2-87xv-37c6
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-252: Unchecked Return Value
Affected Product nimiq-keys
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-40092

To remediate this vulnerability, upgrade all affected nimiq-keys dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nimiq-keys fixed: Latest secure release 
Upgrade nimiq-keys to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for nimiq-keys

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-40092, inspect your project dependencies for nimiq-keys:

inspect dependencies for nimiq-keys

Analyze the terminal output to locate any version of nimiq-keys in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-252: Unchecked Return Value, where the product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions. In nimiq-keys, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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](https://github.com/nimiq/core-rs-albatross/pull/3708) is formally released as part of [v1.4.0](https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0). ### Workarounds No known workarounds. ### Resources See [PR](https://github.com/nimiq/core-rs-albatross/pull/3708).

CVE-2026-40092 Affected nimiq-keys Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
nimiq-keys
 crates.io
≤ 0.2.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-27w2-87xv-37c6
NVD — CVE-2026-40092 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40092
nimiq-keys Source Repository REPOSITORY
https://github.com/nimiq/core-rs-albatross/pull/3708
Security Fix Commit FIX COMMIT
https://github.com/nimiq/core-rs-albatross/commit/807ee8e99a7ccdc604d49971f292854bfa36754d
nimiq-keys Source Repository REPOSITORY
https://github.com/nimiq/core-rs-albatross
nimiq-keys Release RELEASE
https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0

Frequently Asked Questions

What is CVE-2026-40092?
CVE-2026-40092 is a security vulnerability in nimiq-keys involving Unchecked Ed25519 signature length in TaggedPublicKey::verify causes remote node panic via DHT under CWE-252: Unchecked Return Value.
Which nimiq-keys versions are affected?
Affected versions include releases prior to current release patches across affected packages: nimiq-keys.
What version fixes CVE-2026-40092?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is nimiq-keys affected?
Yes, nimiq-keys is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-40092?
CVE-2026-40092 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-40092?
CVE-2026-40092 is classified under CWE-252: Unchecked Return Value (The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.).
How can I check crates.io dependencies for CVE-2026-40092?
Run the dependency tree command: 'inspect dependencies for nimiq-keys'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-27w2-87xv-37c6",
  "modified" : "2026-06-08T20:14:54Z",
  "published" : "2026-05-15T16:31:22Z",
  "aliases" : [ "CVE-2026-40092" ],
  "summary" : "nimiq-keys: Unchecked Ed25519 signature length in TaggedPublicKey::verify causes remote node panic via DHT",
  "details" : "### Impact\nA 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.\n\n### Patches\n[The patch for this vulnerability](https://github.com/nimiq/core-rs-albatross/pull/3708) is formally released as part of [v1.4.0](https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0).\n\n### Workarounds\nNo known workarounds.\n\n### Resources\nSee [PR](https://github.com/nimiq/core-rs-albatross/pull/3708).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "nimiq-keys"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/nimiq/core-rs-albatross/security/advisories/GHSA-27w2-87xv-37c6"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40092"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nimiq/core-rs-albatross/pull/3708"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nimiq/core-rs-albatross/commit/807ee8e99a7ccdc604d49971f292854bfa36754d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/nimiq/core-rs-albatross"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/nimiq/core-rs-albatross/releases/tag/v1.4.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-252" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-15T16:31:22Z",
    "nvd_published_at" : "2026-05-20T22:16:36Z"
  }
}