Medium severity · published Jul 8, 2026
CVE-2026-58251
NATS Server: Queue Subscribe Authz Bypass
6.5
CVSS
0.5%
EPSS
No
On KEV
Description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, an authenticated user with subscription deny permissions could bypass a plain subject deny rule by using a queue subscription, because queue-specific deny evaluation could override the plain subject deny result when the queue name itself was not denied. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NA
nats-server · nats-io
< 2.11.16; >= 2.12.0-RC.1, < 2.12.7 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-58251
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-58251
Patch
https://github.com/nats-io/nats-server/commit/013586288078def45a6788096924eb4d150db65c
Patch
https://github.com/nats-io/nats-server/commit/79c2f6e9ff87f594596337b6427dda85c38d1fe1
Patch
https://github.com/nats-io/nats-server/commit/b9ffb63b85e7db3d25a13b2e234f5f7f7c13164d
Release Notes
https://github.com/nats-io/nats-server/releases/tag/v2.11.16
Release Notes
https://github.com/nats-io/nats-server/releases/tag/v2.12.7
Release Notes
https://github.com/nats-io/nats-server/releases/tag/v2.14.0
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