CVE-2026-29785: CWE-476: NULL Pointer Dereference in nats-io nats-server
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.
AI Analysis
Technical Summary
The vulnerability CVE-2026-29785 affects nats-io nats-server versions before 2.11.14 and 2.12.5. It is a NULL pointer dereference (CWE-476) that leads to a server panic and crash when the leafnode feature is enabled and compression is active. The issue can be triggered by any unauthenticated user able to connect, occurring before authentication. Compression is enabled by default when leafnodes are used, making this a significant risk. The vendor has released fixed versions 2.11.14 and 2.12.5 that resolve the vulnerability. Red Hat advisories confirm the fix and provide updated packages.
Potential Impact
Successful exploitation causes a denial of service by crashing the nats-server, impacting availability. There is no impact on confidentiality or integrity as per the CVSS vector. The attack requires network access to the leafnode port and can be performed without authentication, increasing risk. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix is available in nats-server versions 2.11.14 and 2.12.5. Users should upgrade to these or later versions to remediate the vulnerability. As a temporary workaround, disabling compression on the leafnode port prevents the crash. Follow vendor advisories for updated packages and instructions. No other mitigations are specifically recommended by the vendor.
CVE-2026-29785: CWE-476: NULL Pointer Dereference in nats-io nats-server
Description
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.
CVSS v3.1
Score 7.5high
Affected software
pkg:github/nats-io/nats-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-29785 affects nats-io nats-server versions before 2.11.14 and 2.12.5. It is a NULL pointer dereference (CWE-476) that leads to a server panic and crash when the leafnode feature is enabled and compression is active. The issue can be triggered by any unauthenticated user able to connect, occurring before authentication. Compression is enabled by default when leafnodes are used, making this a significant risk. The vendor has released fixed versions 2.11.14 and 2.12.5 that resolve the vulnerability. Red Hat advisories confirm the fix and provide updated packages.
Potential Impact
Successful exploitation causes a denial of service by crashing the nats-server, impacting availability. There is no impact on confidentiality or integrity as per the CVSS vector. The attack requires network access to the leafnode port and can be performed without authentication, increasing risk. No known exploits in the wild have been reported.
Mitigation Recommendations
A fix is available in nats-server versions 2.11.14 and 2.12.5. Users should upgrade to these or later versions to remediate the vulnerability. As a temporary workaround, disabling compression on the leafnode port prevents the crash. Follow vendor advisories for updated packages and instructions. No other mitigations are specifically recommended by the vendor.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-04T16:26:02.899Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://access.redhat.com/security/cve/CVE-2026-29785","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:22347","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:21769","vendor":"Red Hat"},{"url":"https://access.redhat.com/errata/RHSA-2026:23345","vendor":"Red Hat"}]
Threat ID: 69c43f15f4197a8e3b7dafd6
Added to database: 03/25/2026, 20:01:25 UTC
Last enriched: 07/30/2026, 01:38:26 UTC
Last updated: 07/31/2026, 21:26:48 UTC
Views: 98
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