VulnerabilityAnalyzed

CVE-2026-42934

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module.

MEDIUM 6.3EPSS 0.73%

Does this matter?

Lower severity and a low EPSS score (0.73%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.3 MEDIUMCVSS: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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.73% probability · 52th percentile
CISA KEV: Not listed
Weakness: CWE-125
Affected: f5/dos · f5/nginx gateway fabric · f5/nginx ingress controller · f5/nginx instance manager · f5/nginx open source · f5/nginx plus · f5/waf
Source: f5sirt@f5.com

References

https://my.f5.com/manage/s/article/K000161028Mitigation, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.