What’s Vulnerable › Vulnerabilities

CVE-2021-3127

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-03-16 · updated 2026-06-17
• Weakness: CWE-755

Description

NATS Server 2.x before 2.2.0 and JWT library before 2.0.1 have Incorrect Access Control because Import Token bindings are mishandled.

Affected products

• nats-io nats-server: from 2.0.0 before 2.2.0 — fixed in 2.2.0
• Nats Jwt Library: before 2.0.1 — fixed in 2.0.1

How to fix

Upgrade to a fixed version: nats-io nats-server 2.2.0; Nats Jwt Library 2.0.1. Check the vendor advisory for mitigations.

References

• https://advisories.nats.io/CVE/CVE-2021-3127.txt
• https://advisories.nats.io/CVE/CVE-2021-3127.txt

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