Out-of-bounds read in NGINX Plus and NGINX Open Source - CVE-2026-48142
Published: June 18, 2026
Vulnerability identifier: #VU134864
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-2026-48142
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: F5 Networks
Affected software:
NGINX Plus
NGINX Open Source
NGINX Plus
NGINX Open Source
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose limited memory contents or cause a worker process restart.
The vulnerability exists due to out-of-bounds read in ngx_http_charset_module when serving or proxying content through a location block configured with both source_charset utf-8 and a charset directive. A remote attacker can send crafted requests to disclose limited memory contents or cause a worker process restart.
This is a data plane issue only, and exploitation also depends on conditions beyond the attacker's control.
How to mitigate CVE-2026-48142
Install security update from vendor's website.