CVE-2026-33249

mediumpriority · track · 0OT risk · elevatedEPSS 0.002 · 15 %ileDEEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.24% (15th) EPSS
CVSS 4.3 · medium
Is it mine?
14 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · osv · cert_bund

EPSS · scored 2026-10-27

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.11.0 and prior to versions 2.11.15 and 2.12.6, a valid client which uses message tracing headers can indicate that the trace messages can be sent to an arbitrary valid subject, including those to which the client does not have publish permission. The payload is a valid trace message and not chosen by the attacker. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

01

cvss

Technical severity, 0–10. One row per scoring source.

4.3
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · ENISA EU
v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · security-advisories@github.comexploitability 2.8 · impact 1.4
v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:Nsecondary · OSV
v3.14mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-863USCWE-863US
04

affected products (14)

Products and version ranges known to be affected.

05

advisories (4)

Vendor and ecosystem advisories describing this.

  • WID-SEC-W-2026-0858NATS Server: Mehrere SchwachstellenDeutsch2026-03-24csaf · cert_bundDE

    Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in NATS Server ausnutzen, um Informationen offenzulegen oder zu manipulieren, einen Denial-of-Service zu verursachen und Sicherheitsmechanismen zu umgehen.

  • GHSA-8m2x-3m6q-6w8jNATS: Message tracing can be redirected to arbitrary subject2026-03-24ghsa · osvUS

    ### Background NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing. The nats-server supports telemetry on messages, using the per-message NATS headers. ### Problem Description A valid client which uses message tracing headers can indicate that the trace messages can be sent to an arbitrary valid subject, including those to which the client does not have publish permission. The payload is a valid trace message and not chosen by the attacker. ### Affected Versions Any version before v2.12.6 or v2.11.15 ### Workarounds None.

  • BIT-nats-2026-33249NATS: Message tracing can be redirected to arbitrary subject2026-03-30vendor · osvUS

    NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.11.0 and prior to versions 2.11.15 and 2.12.6, a valid client which uses message tracing headers can indicate that the trace messages can be sent to an arbitrary valid subject, including those to which the client does not have publish permission. The payload is a valid trace message and not chosen by the attacker. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.

  • GO-2026-4826NATS: Message tracing can be redirected to arbitrary subject in github.com/nats-io/nats-server2026-03-26vendor · osvUS

    NATS: Message tracing can be redirected to arbitrary subject in github.com/nats-io/nats-server

06

also known as (6)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvcert_bundnvdNVDCVE.orgMITRE
published 2026-03-25modified 2026-06-17
08

references (8)

External citations — patches, advisories, analysis.

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