CVE-2026-58214: linuxfoundation nats-server Incorrect Authorization
Vulnerability summary
CVE-2026-58214 is a medium (CVSS 4.3) Incorrect Authorization vulnerability in linuxfoundation nats-server. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2Timeline
- 08-07-2026PublishedVulnerability first disclosed.
- 09-07-2026Last modifiedVulnerability information updated.
Description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an authenticated MQTT client could subscribe to the internal $MQTT.deliver.pubrel subject family, bypassing configured subscribe permissions and exposing MQTT QoS2 protocol metadata for sessions in the account. This issue is fixed in versions 2.14.3 and 2.12.12.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- NVDNIST4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.35%
Chance of exploitation in the next 30 days
Percentile
27%
Versus all other CVEs
30-day change
0.00 pp
From 0.35% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- nats-serverAll versions (No fix recorded) | < 2.14.3-1
Linuxfoundation1 product
- nats-server< 2.12.12 | ≥ 2.14.0, < 2.14.3
Nats-io1 product
- nats-server< 2.12.12 | ≥ 2.14.0-RC.1, < 2.14.3
Ubuntu1 product
- nats-serverAll versions (No fix recorded)
4 vendors · 4 products
References
8 links- github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfjX Refsource CONFIRMREPORTVendor Advisory