Out-of-bounds read in NGINX Open Source and NGINX Plus - CVE-2026-42934
Published: May 14, 2026
Vulnerability identifier: #VU131374
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-42934
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: F5 Networks
Affected software:
NGINX Open Source
NGINX Plus
NGINX Open Source
NGINX Plus
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose limited memory contents or cause a denial of service.
The vulnerability exists due to out-of-bounds read in ngx_http_charset_module when processing requests with charset, source_charset, charset_map, and proxy_pass configured with buffering disabled. A remote attacker can send crafted requests to disclose limited memory contents or cause a denial of service.
This issue affects the data plane only and requires the specific configuration to be enabled.
How to mitigate CVE-2026-42934
Install security update from vendor's website.