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TI-2026-31131 Aliases CVE-2026-42934GHSA-6vmc-2wh4-77qp

NGINX ngx_http_charset_module vulnerability

Priority LOW 29CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
Low · None · Low
Fix status
Partial Red Hat: 4 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00731 54th percentileScored 2026-11-07
Fix Partial NGINX Plus (F5): R37, R36 P4, R32 P6NGINX Open Source (F5): 1.31.0, 1.30.1Red Hat: 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
F5NGINX PlusR36 to before R36 P4; R32 to before R32 P6R37, R36 P4, R32 P6Patch availableCNA
F5NGINX Open Source0.3.50 to before 1.30.11.31.0, 1.30.1Patch availableCNA
  • NGINX Plus VendorF5 Affected R36 to before R36 P4; R32 to before R32 P6 Fixed in R37, R36 P4, R32 P6 Patch available CNA
  • NGINX Open Source VendorF5 Affected 0.3.50 to before 1.30.1 Fixed in 1.31.0, 1.30.1 Patch available CNA

CPE configurations NVD · 8

CPEVersionsRoleVendor
cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:*4.3.0 – 4.7.0VulnerableF5
cpe:2.3:a:f5:dos:4.8.0:*:*:*:*:nginx:*:*4.8.0VulnerableF5
cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*1.3.0 – 1.6.2; 2.0.0 – 2.6.0VulnerableF5
cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:*3.5.0 – 3.7.2; 4.0.0 – 4.0.1; 5.0.0 – 5.4.2VulnerableF5
cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:*2.16.0 – 2.22.0VulnerableF5
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*0.3.50 – 0.9.7; 1.0.0 – 1.30.0VulnerableF5
cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*r32 – r36VulnerableF5
cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*4.9.0 – 4.16.0; 5.1.0 – 5.8.0; 5.9.0 – 5.12.1VulnerableF5
  • cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* Versions 4.3.0 – 4.7.0 Vulnerable ·F5
  • cpe:2.3:a:f5:dos:4.8.0:*:*:*:*:nginx:*:* Versions 4.8.0 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* Versions 1.3.0 – 1.6.2; 2.0.0 – 2.6.0 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:*:*:*:* Versions 3.5.0 – 3.7.2; 4.0.0 – 4.0.1; 5.0.0 – 5.4.2 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* Versions 2.16.0 – 2.22.0 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* Versions 0.3.50 – 0.9.7; 1.0.0 – 1.30.0 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* Versions r32 – r36 Vulnerable ·F5
  • cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* Versions 4.9.0 – 4.16.0; 5.1.0 – 5.8.0; 5.9.0 – 5.12.1 Vulnerable ·F5

Remediation

  • Fix · CNA NGINX Plus (F5) Fixed in R37, R36 P4, R32 P6
  • Fix · CNA NGINX Open Source (F5) Fixed in 1.31.0, 1.30.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    F5 NGINX Open Source 1.30.1

    6 records Highest priority Priority HIGH 1 HIGH, 5 LOW

    Other records, highest priority first

    • TI-2026-31136 NGINX ngx_http_rewrite_module vulnerabilityPriority HIGH 78
    • TI-2026-31137 NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerabilityPriority LOW 38
    • TI-2026-29212 NGINX ngx_quic_module vulnerabilityPriority LOW 37
    Show all 6 records →
  • Release ·

    F5 NGINX Plus R32 P6, R36 P4

    5 records Highest priority Priority HIGH 1 HIGH, 4 LOW

    Other records, highest priority first

    • TI-2026-31136 NGINX ngx_http_rewrite_module vulnerabilityPriority HIGH 78
    • TI-2026-31137 NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerabilityPriority LOW 38
    • TI-2026-29212 NGINX ngx_quic_module vulnerabilityPriority LOW 37
    Show all 5 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Lightspeed proxy 1AffectedNo fix yet: Fix deferred
Not affected: 1 product
  • Red Hat Hardened Images

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42934
  2. 2026-10-03 Alias added: GHSA-6vmc-2wh4-77qp

References

Patch 1

  • TI-2026-31136 NGINX ngx_http_rewrite_module vulnerability CVSS 4.0CRITICAL 9.2
  • TI-2026-08132 NGINX ngx_http_rewrite_module vulnerability CVSS 4.0CRITICAL 9.2
  • TI-2026-30432 NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability CVSS 4.0CRITICAL 9.2
  • TI-2026-31137 NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerability CVSS 4.0HIGH 8.3
  • TI-2026-29212 NGINX ngx_quic_module vulnerability CVSS 4.0MEDIUM 6.9
  • TI-2026-35579 NGINX ngx_http_charset_module vulnerability CVSS 4.0MEDIUM 6.3
See all 7 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences