CVE-2026-42934

medium

Description

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset, source_charset, and charset_map and proxy_pass with disabled buffering ("off") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers' 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.

References

Advisories
References

https://my.f5.com/manage/s/article/K000161028

https://www.bleepingcomputer.com/news/security/18-year-old-nginx-vulnerability-allows-dos-potential-rce/

https://thehackernews.com/2026/05/18-year-old-nginx-rewrite-module-flaw.html

https://securityaffairs.com/192132/hacking/nginx-rift-an-18-year-old-flaw-in-the-worlds-most-deployed-web-server-just-came-to-light.html

Details

Source: Mitre, NVD

Published: 2026-05-13

Updated: 2026-05-13

Risk Information

CVSS v2

Base Score: 4

Vector: CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 4.8

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Severity: Medium

CVSS v4

Base Score: 6.3

Vector: 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

Severity: Medium

EPSS

EPSS: 0.00035