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TI-2026-22033 Aliases CVE-2026-27651GHSA-82w2-x7hf-5h8r

NGINX ngx_mail_auth_http_module vulnerability

Priority MEDIUM 45CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-476.

Summary

When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. 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 0.00955 61st percentileScored 2026-11-07
Fix Fixed NGINX Open Source (F5): 1.29.7, 1.28.3NGINX Plus (F5): R36 P3, R35 P2, R32 P5Red Hat: 15 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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; 0.5.15 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; 0.5.15 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 · 12

CPEVersionsRoleVendor
cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*0.5.15 – 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:*:*:*:*:*:*:*:*r33 to before r35VulnerableF5
cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:*r32VulnerableF5
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: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_open_source:*:*:*:*:*:*:*:* Versions 0.5.15 – 0.9.7; 1.0.0 to before 1.28.3; 1.29.0 to before 1.29.7 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:* Versions r33 to before r35 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r32:-:*:*:*:*:*:* Versions r32 Vulnerable ·F5
  • 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: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
Show 2 more CPE
CPEVersionsRoleVendor
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_plus:r36:p1:*:*:*:*:*:* Versions r36 p1 Vulnerable ·F5
  • cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:* Versions r36 p2 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 15 advisories

  • RHSA-2026:15966 Released 2026-05-11 · Red Hat rating Important
    nginx:1.26 security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) nginx-2:1.26.3-1.module+el9.6.0+24255+10832c07.2.aarch64::nginx:1.26, nginx-2:1.26.3-1.module+el9.6.0+24255+10832c07.2.ppc64le::nginx:1.26, nginx-2:1.26.3-1.module+el9.6.0+24255+10832c07.2.s390x::nginx:1.26 +32
  • RHSA-2026:15945 Released 2026-05-11 · Red Hat rating Important
    nginx:1.24 security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) nginx-1:1.24.0-4.module+el9.6.0+24259+49d2cefe.2.aarch64::nginx:1.24, nginx-1:1.24.0-4.module+el9.6.0+24259+49d2cefe.2.ppc64le::nginx:1.24, nginx-1:1.24.0-4.module+el9.6.0+24259+49d2cefe.2.s390x::nginx:1.24 +32
  • RHSA-2026:15943 Released 2026-05-11 · Red Hat rating Important
    nginx:1.24 security update
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) nginx-1:1.24.0-1.module+el9.4.0+24260+3e6db809.4.aarch64::nginx:1.24, nginx-1:1.24.0-1.module+el9.4.0+24260+3e6db809.4.ppc64le::nginx:1.24, nginx-1:1.24.0-1.module+el9.4.0+24260+3e6db809.4.s390x::nginx:1.24 +32
Show 12 more Red Hat advisories
  • RHSA-2026:15942 Released 2026-05-11 · Red Hat rating Important
    nginx security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.0) nginx-1:1.20.1-10.el9_0.3, nginx-all-modules-1:1.20.1-10.el9_0.3, nginx-filesystem-1:1.20.1-10.el9_0.3 +5
  • RHSA-2026:14836 Released 2026-05-07 · Red Hat rating Important
    nginx security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) nginx-1:1.20.1-14.el9_2.5, nginx-all-modules-1:1.20.1-14.el9_2.5, nginx-core-1:1.20.1-14.el9_2.5 +6
  • RHSA-2026:13839 Released 2026-05-05 · Red Hat rating Important
    nginx security update
    • Red Hat CodeReady Linux Builder EUS (v.9.4) nginx-mod-devel-1:1.20.1-16.el9_4.5
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) nginx-1:1.20.1-16.el9_4.5, nginx-all-modules-1:1.20.1-16.el9_4.5, nginx-core-1:1.20.1-16.el9_4.5 +6
  • RHSA-2026:13680 Released 2026-05-05 · Red Hat rating Important
    nginx security update
    • Red Hat CodeReady Linux Builder EUS (v.9.6) nginx-mod-devel-2:1.20.1-22.el9_6.5
    • Red Hat Enterprise Linux AppStream EUS (v.9.6) nginx-2:1.20.1-22.el9_6.5, nginx-all-modules-2:1.20.1-22.el9_6.5, nginx-core-2:1.20.1-22.el9_6.5 +6
  • RHSA-2026:13634 Released 2026-05-05 · Red Hat rating Important
    nginx security update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) nginx-2:1.26.3-1.el10_0.8, nginx-all-modules-2:1.26.3-1.el10_0.8, nginx-core-2:1.26.3-1.el10_0.8 +6
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) nginx-mod-devel-2:1.26.3-1.el10_0.8
  • RHSA-2026:10065 Released 2026-04-23 · Red Hat rating Important
    Red Hat Update Infrastructure 5.1 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9, registry.redhat.io/rhui5/installer-rhel9 +1
  • 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
  • RHSA-2026:7343 Released 2026-04-09 · Red Hat rating Important
    nginx:1.26 security update
    • Red Hat Enterprise Linux AppStream (v. 9) nginx-2:1.26.3-2.module+el9.7.0+24173+4204b761.1.aarch64::nginx:1.26, nginx-2:1.26.3-2.module+el9.7.0+24173+4204b761.1.ppc64le::nginx:1.26, nginx-2:1.26.3-2.module+el9.7.0+24173+4204b761.1.s390x::nginx:1.26 +32
  • RHSA-2026:7002 Released 2026-04-08 · Red Hat rating Important
    nginx security update
    • Red Hat Enterprise Linux AppStream (v. 9) nginx-2:1.20.1-24.el9_7.2, nginx-core-2:1.20.1-24.el9_7.2, nginx-mod-mail-2:1.20.1-24.el9_7.2
  • RHSA-2026:6923 Released 2026-04-07 · Red Hat rating Important
    nginx:1.24 security update
    • Red Hat Enterprise Linux AppStream (v. 9) nginx-1:1.24.0-5.module+el9.7.0+24151+c43a3acf.2.aarch64::nginx:1.24, nginx-1:1.24.0-5.module+el9.7.0+24151+c43a3acf.2.ppc64le::nginx:1.24, nginx-1:1.24.0-5.module+el9.7.0+24151+c43a3acf.2.s390x::nginx:1.24 +32
  • RHSA-2026:6907 Released 2026-04-07 · Red Hat rating Important
    nginx:1.24 security update
    • Red Hat Enterprise Linux AppStream (v. 8) nginx-1:1.24.0-3.module+el8.10.0+24155+8a5ade52.aarch64::nginx:1.24, nginx-1:1.24.0-3.module+el8.10.0+24155+8a5ade52.ppc64le::nginx:1.24, nginx-1:1.24.0-3.module+el8.10.0+24155+8a5ade52.s390x::nginx:1.24 +28
  • RHSA-2026:6906 Released 2026-04-07 · Red Hat rating Important
    nginx security update
    • Red Hat Enterprise Linux AppStream (v. 10) nginx-2:1.26.3-2.el10_1.1, nginx-core-2:1.26.3-2.el10_1.1, nginx-mod-mail-2:1.26.3-2.el10_1.1

Fixed in the same release

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

  • Release ·

    F5 NGINX Open Source 1.28.3, 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-2026-25155 NGINX ngx_http_mp4_module vulnerabilityPriority MEDIUM 41
    • TI-2026-22141 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-2026-25155 NGINX ngx_http_mp4_module vulnerabilityPriority MEDIUM 41
    • TI-2026-22952 NGINX ngx_mail_proxy_module vulnerabilityPriority LOW 28
    Show all 4 records →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat CodeReady Linux Builder EUS (v.9.4)Fixed RHSA-2026:13839
Red Hat CodeReady Linux Builder EUS (v.9.6)Fixed RHSA-2026:13680
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:6906
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:6907
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:6923, RHSA-2026:7002, RHSA-2026:7343
Red Hat Enterprise Linux AppStream E4S (v.9.0)Fixed RHSA-2026:15942
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:14836
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:13634
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2026:13839, RHSA-2026:15943
Red Hat Enterprise Linux AppStream EUS (v.9.6)Fixed RHSA-2026:13680, RHSA-2026:15945, RHSA-2026:15966
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:13634
Red Hat Hardened ImagesFixed RHSA-2026:8346
Red Hat Update Infrastructure 5Fixed RHSA-2026:10065
Not affected: 5 products
  • Red Hat Enterprise Linux AppStream (v. 10)
  • Red Hat Enterprise Linux AppStream (v. 9)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)
  • Red Hat Update Infrastructure 5

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27651
  2. 2026-10-03 Alias added: GHSA-82w2-x7hf-5h8r

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