How severe is GHSA-9r5x-fjv3-q6h4?

GHSA-9r5x-fjv3-q6h4 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-9r5x-fjv3-q6h4?

GHSA-9r5x-fjv3-q6h4 affects the following packages: github.com/nats-io/jwt/v2 (Go), github.com/nats-io/nats-server/v2 (Go), github.com/nats-io/jwt (Go). Ecosystems affected: Go.

How do I fix GHSA-9r5x-fjv3-q6h4?

Update github.com/nats-io/jwt/v2 to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9r5x-fjv3-q6h4 is resolved across your whole dependency graph.

How do I detect GHSA-9r5x-fjv3-q6h4 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/nats-io/jwt/v2. 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 GHSA-9r5x-fjv3-q6h4 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 GHSA-9r5x-fjv3-q6h4?

O3 pinpoints whether GHSA-9r5x-fjv3-q6h4 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 GHSA-9r5x-fjv3-q6h4 actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-9r5x-fjv3-q6h4, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-9r5x-fjv3-q6h4?

GHSA-9r5x-fjv3-q6h4 has an EPSS (Exploit Prediction Scoring System) score of 1.5%, placing it in the 70th 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 GHSA-9r5x-fjv3-q6h4?

GHSA-9r5x-fjv3-q6h4 is classified as CWE-755 (CWE-755). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-9r5x-fjv3-q6h4 published, and has it been updated?

GHSA-9r5x-fjv3-q6h4 was published on February 15, 2022 and was last updated on February 4, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

Withdrawn — this advisory has been retracted

🐹 Go

GHSA-9r5x-fjv3-q6h4

HIGH

Duplicate Advisory: Incorrect Access Control in github.com/nats-io/jwt and github.com/nats-io/nats-server/v2

Also known asBIT-nats-2021-3127CVE-2021-3127 GHSA-62mh-w5cv-p88c GHSA-j756-f273-xhp4GO-2022-0386

Published

Feb 15, 2022

Updated

Feb 4, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

1.5%probability of exploitation in next 30 days

Lower Risk70th percentile+1.17%

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

3 pkgs affected

🐹github.com/nats-io/jwt/v2🐹github.com/nats-io/nats-server/v2🐹github.com/nats-io/jwt

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

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-62mh-w5cv-p88c (for github.com/nats-io/jwt) and GHSA-j756-f273-xhp4 (for github.com/nats-io/nats-server). This link is maintained to preserve external references.

Original Description

NATS Server (github.com/nats-io/nats-server/v2/server) 2.x before 2.2.0 and JWT library (github.com/nats-io/jwt/v2) before 2.0.1 have Incorrect Access Control because Import Token bindings are mishandled.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/nats-io/jwt/v2`	all versions	2.0.1
🐹Go	`github.com/nats-io/nats-server/v2`	all versions	2.2.0
🐹Go	`github.com/nats-io/jwt`	all versions	1.2.3-0.20210314221642-a826c77dc9d2

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

NATS Server 2.x before 2.2.0 and JWT library before 2.0.1 have Incorrect…

advisories.nats.ioNVDMar 2021

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/jwt/v2. 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/jwt/v2 to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9r5x-fjv3-q6h4 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 GHSA-9r5x-fjv3-q6h4 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 GHSA-9r5x-fjv3-q6h4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-62mh-w5cv-p88c (for github.com/nats-io/jwt) and GHSA-j756-f273-xhp4 (for github.com/nats-io/nats-server). This link is maintained to preserve external references. ## Original Description NATS Server (github.com/nats-io/nats-server/v2/server) 2.x before 2.2.0 and JWT library (github.com/nats-io/jwt/v2) before 2.0.1 have Incorrect Access Control because Import Token bindings are mishandled.

O3 Security · Impact-Aware SCA

Is GHSA-9r5x-fjv3-q6h4 in your dependencies?

O3 detects GHSA-9r5x-fjv3-q6h4 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