Vulnerability · Published Nov 6, 2020 · Assigned by mitre
CVE-2020-26521
High 7.5
In plain English
A high-severity security flaw in the golang-github-nats-io-jwt package (Debian). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.2% (higher than 82% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)7.5High
Exploit odds (30 days)2.2%top 17.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
The JWT library in NATS nats-server before 2.1.9 allows a denial of service (a nil dereference in Go code).
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-github-nats-io-jwt | 2.2.0-1 | DEBIAN-CVE-2020-26521 |
| Debian:13 | golang-github-nats-io-jwt | 2.2.0-1 | DEBIAN-CVE-2020-26521 |
| Debian:14 | golang-github-nats-io-jwt | 2.2.0-1 | DEBIAN-CVE-2020-26521 |
| Go | github.com/nats-io/jwt | 1.1.0 | GO-2022-0402 |
| Go | github.com/nats-io/jwt | 1.1.0 | GHSA-h2fg-54x9-5qhq |
| Go | github.com/nats-io/nats-server/v2 | 2.1.9 | GHSA-hmm9-r2m2-qg9w |
| Ubuntu:22.04:LTS | golang-github-nats-io-jwt | no fix listed | UBUNTU-CVE-2020-26521 |
| Ubuntu:24.04:LTS | golang-github-nats-io-jwt | no fix listed | UBUNTU-CVE-2020-26521 |
| Ubuntu:25.10 | golang-github-nats-io-jwt | no fix listed | UBUNTU-CVE-2020-26521 |
| Ubuntu:26.04:LTS | golang-github-nats-io-jwt | no fix listed | UBUNTU-CVE-2020-26521 |
| Ubuntu:26.10 | golang-github-nats-io-jwt | no fix listed | UBUNTU-CVE-2020-26521 |
Affected products (as reported)
References
- https://github.com/nats-io/nats-server/commits/master x_refsource_MISC
- http://www.openwall.com/lists/oss-security/2020/11/02/2 x_refsource_CONFIRM
- FEDORA-2020-2c8851d48b vendor-advisory, x_refsource_FEDORA