CVE-2026-48142

NGINX ngx_http_charset_module vulnerability

State: Published
Severity: 6.3 Medium
Published: Jun 17, 2026
Updated: Jun 17, 2026
Reserved: Jun 2, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	6.3 Medium	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N	f5
3.1	4.8 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L	f5

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
NGINX Open SourceF5	1.13.10 to before 1.31.2Affected 1.30.0 to before 1.30.3Affected
NGINX PlusF5	37.0 to before 37.0.2.1Affected R36 to before R36 P6Affected

References

https://my.f5.com/manage/s/article/K000161585vendor-advisory

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