CVE-2026-48142: F5 Dos

Medium severity, CVSS 4.8. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• F5 Dos: from 4.3.0, up to and including 4.7.0; version 4.9.0 only
• F5 Nginx Gateway Fabric: from 1.3.0, up to and including 1.6.2; from 2.0.0, up to and including 2.6.3
• F5 Nginx Ingress Controller: from 3.5.0, up to and including 3.7.2; from 4.0.0, up to and including 4.0.1; from 5.0.0, up to and including 5.5.0
• F5 Nginx Instance Manager: from 2.17.0, up to and including 2.22.0
• F5 Nginx Open Source: from 1.0.0, up to and including 1.30.2; from 1.31.0, up to and including 1.31.1
• F5 Nginx Plus: from 37.0.0.1, before 37.0.2.1 (fixed in 37.0.2.1); from r33, before r36 (fixed in r36); version r36 only
• F5 Waf: from 4.10.0, up to and including 4.16.0; from 5.2.0, up to and including 5.8.0; from 5.9.0, up to and including 5.13.1

Published 2026-06-17. Last modified 2026-08-11.