HOMEVULNERABILITIESCVE-2026-33219
MEDIUM

CVE-2026-33219

CWE-770Published: March 25, 2026· Updated: Mar 26, 2026

5.3
CVSS v3.1
EPSS:0.07%probability of exploitation in 30 daysPercentile:20.4th

Official Description

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, a malicious client which can connect to the WebSockets port can cause unbounded memory use in the nats-server before authentication; this requires sending a corresponding amount of data. This is a milder variant of CVE-2026-27571. That earlier issue was a compression bomb, this vulnerability is not. Attacks against this new issue thus require significant client bandwidth. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable websockets if not required for project deployment.

NVD Source

Technical Analysis

CVE-2026-33219 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityLow
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected Vendors & Products

linuxfoundation1 product
nats-server
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://advisories.nats.io/CVE/secnote-2026-02.txt
ADVISORYhttps://advisories.nats.io/CVE/secnote-2026-11.txt
ADVISORYhttps://github.com/advisories/GHSA-qrvq-68c2-7grw
ADVISORYhttps://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7j

All References (4)

→
https://advisories.nats.io/CVE/secnote-2026-02.txtMitigation · Vendor Advisory
→
https://advisories.nats.io/CVE/secnote-2026-11.txtMitigation · Vendor Advisory
→
https://github.com/advisories/GHSA-qrvq-68c2-7grwMitigation · Vendor Advisory
→
https://github.com/nats-io/nats-server/security/advisories/GHSA-8r68-gvr4-jh7jMitigation · Vendor Advisory

Quick Facts

CVE IDCVE-2026-33219
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessCWE-770
CISA KEVNo
EPSS (30d)0.07%
Affected1 vendor
PublishedMar 25, 2026

Related CVEs (CWE-770)

CVE-2026-12818
9.3
CVE-2026-42786
8.7
CVE-2026-35469
8.7
CVE-2026-32145
8.7
CVE-2026-43973
8.7
CVE-2026-48854
8.7

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-33219 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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