CVE-2026-48142 NGINX ngx_http_charset_module vulnerability
Remote attackers can trigger a heap buffer over-read in NGINX when specific charset configurations are used, leading to memory disclosure or service restart.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48142?
CVE-2026-48142 is a medium-severity vulnerability in F5 NGINX Open Source, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When content is served or proxied through a location block with both source_charset utf-8; and a charset directive (for example, charset koi8-r;) configured, remote, unauthenticated attackers can send requests (in conjunction with conditions beyond their control) to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Weakness: CWE-125
Which versions are affected by CVE-2026-48142?
3 open source packages ship an affected version, including nginx, nginx-gateway and nginx-gateway-fabric. It affects 7 products.
| Package | Affected | Fixed in |
|---|---|---|
nginx Bitnami | From 1.0.0 | 1.30.3, 1.31.2 |
nginx-gateway Bitnami | From 1.0.0 | 1.30.3, 1.31.2 |
nginx-gateway-fabric Bitnami | From 1.3.0 | 2.6.4 |
Products include F5 Dos, F5 Nginx Gateway Fabric, F5 Nginx Ingress Controller, F5 Nginx Instance Manager, F5 Nginx Open Source, F5 Nginx Plus and 1 more.
How do I fix CVE-2026-48142?
Upgrade nginx to a fixed version for your release line: 1.30.3 or 1.31.2.
Is CVE-2026-48142 being exploited?
There is no known exploitation of CVE-2026-48142 in the wild and no public exploit code.
Other vulnerabilities in F5 NGINX Open Source
- CVE-2026-42055 NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability
- CVE-2026-42945 NGINX ngx_http_rewrite_module vulnerability
- CVE-2026-42946 NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerability
- CVE-2026-40460 NGINX ngx_quic_module vulnerability
- CVE-2026-40701 NGINX ngx_http_ssl_module vulnerability
Sources
Also known as ALPINE-CVE-2026-48142, AZL-91176, BELL-CVE-2026-48142, BIT-nginx-2026-48142, BIT-nginx-gateway-2026-48142, BIT-nginx-gateway-fabric-2026-48142 and 13 more.