nats-io nats-server up to 2.11.14/2.12.5 /debug/vars insertion of sensitive information into debugging code

CVSS Meta Temp Score
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CTI Interest Score
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5.8$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic was found in nats-io nats-server up to 2.11.14/2.12.5. This issue affects some unknown processing of the file /debug/vars. Executing a manipulation can lead to insertion of sensitive information into debugging code. This vulnerability is registered as CVE-2026-33247. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in nats-io nats-server up to 2.11.14/2.12.5. It has been declared as problematic. This vulnerability affects an unknown function of the file /debug/vars. The manipulation with an unknown input leads to a insertion of sensitive information into debugging code vulnerability. The CWE definition for the vulnerability is CWE-215. The product inserts sensitive information into debugging code, which could expose this information if the debugging code is not disabled in production. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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, if a nats-server is run with static credentials for all clients provided via argv (the command-line), then those credentials are visible to any user who can see the monitoring port, if that too is enabled. The `/debug/vars` end-point contains an unredacted copy of argv. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, configure credentials inside a configuration file instead of via argv, and do not enable the monitoring port if using secrets in argv. Best practice remains to not expose the monitoring port to the Internet, or to untrusted network sources.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-33247 since 03/18/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1592.

The vulnerability scanner Nessus provides a plugin with the ID 303839 (Linux Distros Unpatched Vulnerability : CVE-2026-33247), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.11.15 or 2.12.6 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (303839). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

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Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.3
NVD Vector: 🔒

CNA Base Score: 7.4
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Insertion of sensitive information into debugging code
CWE: CWE-215 / CWE-200 / CWE-284
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 303839
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-33247

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: nats-server 2.11.15/2.12.6

Timelineinfo

03/18/2026 CVE reserved
03/25/2026 +7 days Advisory disclosed
03/25/2026 +0 days VulDB entry created
04/01/2026 +7 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-x6g4-f6q3-fqvv
Status: Confirmed

CVE: CVE-2026-33247 (🔒)
GCVE (CVE): GCVE-0-2026-33247
GCVE (VulDB): GCVE-100-353500

Entryinfo

Created: 03/25/2026 23:00
Updated: 04/01/2026 13:04
Changes: 03/25/2026 23:00 (64), 03/26/2026 22:05 (2), 04/01/2026 13:04 (12)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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