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HIGH severity

xkeys seal encryption used fixed key for all encryptionGHSA-mr45-rx8q-wcm9

HIGHFix: nats-io/nkeys@58fb9d6

GHSA-mr45-rx8q-wcm9 is a high-severity (CVSS 7.5) CWE-321 vulnerability in github.com/nats-io/nkeys. A fix is available for github.com/nats-io/nkeys — see the affected versions and patch details below.

Also known asBIT-nats-2023-46129CVE-2023-46129GO-2023-2163
Published
Updated
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Nov 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-mr45-rx8q-wcm9.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk
0.00%0.32%0.63%0.95%0.1%0.4%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected
🐹github.com/nats-io/nkeys🐹github.com/nats-io/nats-server/v2

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Background

NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing.

The cryptographic key handling library, nkeys, recently gained support for encryption, not just for signing/authentication. This is used in nats-server 2.10 (Sep 2023) and newer for authentication callouts.

Problem Description

The nkeys library's "xkeys" encryption handling logic mistakenly passed an array by value into an internal function, where the function mutated that buffer to populate the encryption key to use. As a result, all encryption was actually to an all-zeros key.

This affects encryption only, not signing.
FIXME: FILL IN IMPACT ON NATS-SERVER AUTH CALLOUT SECURITY.

Affected versions

nkeys Go library:

  • 0.4.0 up to and including 0.4.5
  • Fixed with nats-io/nkeys: 0.4.6

NATS Server:

  • 2.10.0 up to and including 2.10.3
  • Fixed with nats-io/nats-server: 2.10.4

Solution

Upgrade the nats-server.
For any application handling auth callouts in Go, if using the nkeys library, update the dependency, recompile and deploy that in lockstep.

Credits

Problem reported by Quentin Matillat (GitHub @tinou98).

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/nats-io/nkeys≥ 0.4.0&&< 0.4.60.4.6go get github.com/nats-io/nkeys@v0.4.6
🐹Gogithub.com/nats-io/nats-server/v2≥ 2.10.0&&< 2.10.42.10.4go get github.com/nats-io/nats-server/v2@v2.10.4

Affected Products

2 products · 2 configurations
Application
nats-serverlinuxfoundation
≥ 2.10.0 && < 2.10.4
range
Application
nkeysnats
≥ 0.4.0 && < 0.4.6
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/nats-io/nkeys, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update github.com/nats-io/nkeys to 0.4.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mr45-rx8q-wcm9 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant
ProductFixed inAdvisory
Red Hat Openshift distributed tracing 3.0rhosdt/tempo-gateway-rhel8:0.1.2-19RHSA-2023:7663

Frequently Asked Questions

## Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The cryptographic key handling library, nkeys, recently gained support for encryption, not just for signing/authentication. This is used in nats-server 2.10 (Sep 2023) and newer for authentication callouts. ## Problem Description The nkeys library's "xkeys" encryption handling logic mistakenly passed an array by value into an internal function, where the function mutated that buffer to populate the encryption key to use. As a resu
O3 Security · Impact-Aware SCA

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GHSA-mr45-rx8q-wcm9: nkeys — Fixed in 0.4.6