# CVE-2026-90439: nginx: NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_v3_module module

CVE-2026-90439 is fixed in nginx on 1 platform by DEBIAN-CVE-2026-90439 (version 1.30.4-7), released September 20, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-90439
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0026
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 15, 2026

## Description

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_v3_module module. When using HTTP/3 with OpenSSL versions <= OpenSSL 3.5.0 under certain configurations, a limited heap buffer overflow could happen while processing a TLS handshake. This can happen in a non-deterministic manner that is beyond the attacker's control. This may cause a heap buffer overflow in the NGINX worker process leading to a restart and/or limited data corruption.  Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or limited data corruption. There is no control plane exposure; this is a data plane issue only.     Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | nginx Debian 14 | 1.30.4-7 | [DEBIAN-CVE-2026-90439](https://patchblox.com/security/data/fix/linux/debian-cve-2026-90439.md) | Sep 20, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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