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TI-2026-22952 Aliases CVE-2026-28753GHSA-ggr6-fmr8-2m8g

NGINX ngx_mail_proxy_module vulnerability

Priority LOW 28CWE-93Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Partial Red Hat: 1 fixed, 3 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_mail_smtp_module module due to the improper handling of CRLF sequences in DNS responses. This allows an attacker-controlled DNS server to inject arbitrary headers into SMTP upstream requests, leading to potential request manipulation. 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 0.00275 19th percentileScored 2026-11-07
Fix Partial NGINX Open Source (F5): 1.29.7, 1.28.3NGINX Plus (F5): R36 P3, R35 P2, R32 P5Red Hat: 1 advisoryRed Hat: 1 fixed, 3 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 Open Source1.29.0 to before 1.29.7; 0.6.27 to before 1.28.31.29.7, 1.28.3Patch availableCNA
F5NGINX PlusR36 to before R36 P3; R35 to before R35 P2; R34 and later; R33 and later; R32 to before R32 P5R36 P3, R35 P2, R32 P5Patch availableCNA
  • NGINX Open Source VendorF5 Affected 1.29.0 to before 1.29.7; 0.6.27 to before 1.28.3 Fixed in 1.29.7, 1.28.3 Patch available CNA
  • NGINX Plus VendorF5 Affected R36 to before R36 P3; R35 to before R35 P2; R34 and later; R33 and later; R32 to before R32 P5 Fixed in R36 P3, R35 P2, R32 P5 Patch available CNA

CPE configurations NVD · 17

CPEVersionsRoleVendor
cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:*r32 p1VulnerableF5
cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:*r32 p2VulnerableF5
cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:*r32 p3VulnerableF5
cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:*r32 p4VulnerableF5
cpe:2.3:a:f5:nginx_plus:r33:*:*:*:*:*:*:*r33VulnerableF5
cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:*r33 p1VulnerableF5
cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:*r33 p2VulnerableF5
cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:*r33 p3VulnerableF5
cpe:2.3:a:f5:nginx_plus:r34:*:*:*:*:*:*:*r34VulnerableF5
cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:*r34 p1VulnerableF5
  • cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:* Versions r32 p1 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:* Versions r32 p2 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:* Versions r32 p3 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:* Versions r32 p4 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r33:*:*:*:*:*:*:* Versions r33 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:* Versions r33 p1 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:* Versions r33 p2 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:* Versions r33 p3 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r34:*:*:*:*:*:*:* Versions r34 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:* Versions r34 p1 Vulnerable ·F5
Show 7 more CPE
CPEVersionsRoleVendor
cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:*r34 p2VulnerableF5
cpe:2.3:a:f5:nginx_plus:r35:*:*:*:*:*:*:*r35VulnerableF5
cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:*r35 p1VulnerableF5
cpe:2.3:a:f5:nginx_plus:r36:*:*:*:*:*:*:*r36VulnerableF5
cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*r36 p1VulnerableF5
cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*r36 p2VulnerableF5
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*0.6.27 – 0.9.7; 1.0.0 to before 1.28.3; 1.29.0 to before 1.29.7VulnerableF5
  • cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:* Versions r34 p2 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r35:*:*:*:*:*:*:* Versions r35 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:* Versions r35 p1 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r36:*:*:*:*:*:*:* Versions r36 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:* Versions r36 p1 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:* Versions r36 p2 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* Versions 0.6.27 – 0.9.7; 1.0.0 to before 1.28.3; 1.29.0 to before 1.29.7 Vulnerable ·F5

Remediation

  • Fix · CNA NGINX Open Source (F5) Fixed in 1.29.7, 1.28.3
  • Fix · CNA NGINX Plus (F5) Fixed in R36 P3, R35 P2, R32 P5

Red Hat 1 advisory

  • RHSA-2026:8346 Released 2026-04-15 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images nginx-1.30.0-1.hum1@aarch64, nginx-1.30.0-1.hum1@src, nginx-1.30.0-1.hum1@x86_64 +22

Fixed in the same release

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

  • Release ·

    F5 NGINX Open Source 1.28.3, 1.29.7

    6 records Highest priority Priority HIGH 1 HIGH, 3 MEDIUM, 2 LOW

    Other records, highest priority first

    • TI-2026-22036 NGINX ngx_http_dav_module vulnerabilityPriority HIGH 66
    • TI-2026-22033 NGINX ngx_mail_auth_http_module vulnerabilityPriority MEDIUM 45
    • TI-2026-25155 NGINX ngx_http_mp4_module vulnerabilityPriority MEDIUM 41
    Show all 6 records →
  • Release ·

    F5 NGINX Plus R32 P5, R35 P2, R36 P3

    4 records Highest priority Priority HIGH 1 HIGH, 2 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-22036 NGINX ngx_http_dav_module vulnerabilityPriority HIGH 66
    • TI-2026-22033 NGINX ngx_mail_auth_http_module vulnerabilityPriority MEDIUM 45
    • TI-2026-25155 NGINX ngx_http_mp4_module vulnerabilityPriority MEDIUM 41
    Show all 4 records →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:8346

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-28753
  2. 2026-10-03 Alias added: GHSA-ggr6-fmr8-2m8g

References

Advisory 1

  • TI-2026-31136 NGINX ngx_http_rewrite_module vulnerability CVSS 4.0CRITICAL 9.2
  • TI-2026-22036 NGINX ngx_http_dav_module vulnerability CVSS 4.0HIGH 8.8
  • TI-2026-08132 NGINX ngx_http_rewrite_module vulnerability CVSS 4.0CRITICAL 9.2
  • TI-2026-30812 NGINX Open-Source ngx_http_v3_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-2026-42786 NGINX ngx_http_slice_module vulnerability CVSS 4.0HIGH 8.8
See all 25 →

Sources

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