How severe is CVE-2023-46129?

CVE-2023-46129 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-46129?

CVE-2023-46129 affects the following packages: github.com/nats-io/nkeys (Go), github.com/nats-io/nats-server/v2 (Go). Ecosystems affected: Go.

How do I fix CVE-2023-46129?

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 CVE-2023-46129 is resolved across your whole dependency graph.

How do I detect CVE-2023-46129 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/nats-io/nkeys. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2023-46129 if there is no patch (or I can't update yet)?

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.

How does O3 Security protect against CVE-2023-46129?

O3 pinpoints whether CVE-2023-46129 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-46129 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-46129 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-46129?

CVE-2023-46129 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 29th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-46129?

CVE-2023-46129 is classified as CWE-321 (CWE-321), CWE-325 (CWE-325). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-46129 published, and has it been updated?

CVE-2023-46129 was published on October 30, 2023 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2023-46129: xkeys Seal encryption used fixed key for all en…

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk29th percentile+0.22%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

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

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. In nkeys versions 0.4.0 through 0.4.5, corresponding with NATS server versions 2.10.0 through 2.10.3, 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. nkeys Go library 0.4.6, corresponding with NATS Server 2.10.4, has a patch for this issue. No known workarounds are available. For any application handling auth callouts in Go, if using the nkeys library, update the dependency, recompile and deploy that in lockstep.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/nats-io/nkeys`	≥ 0.4.0&&< 0.4.6	0.4.6
🐹Go	`github.com/nats-io/nats-server/v2`	≥ 2.10.0&&< 2.10.4	2.10.4

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/nats-io/nkeys. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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 CVE-2023-46129 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether CVE-2023-46129 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2023-46129. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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. In nkeys versions 0.4.0 through 0.4.5, corresponding with NATS server versions 2.10.0 through 2.10.3, the nkeys library's `xkeys` encryption handling logic mistakenly passed an array by value into an internal function, where the function mutated t

O3 Security · Impact-Aware SCA

Is CVE-2023-46129 in your dependencies?

O3 detects CVE-2023-46129 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2023-46129