{
  "threat_severity" : "Important",
  "public_date" : "2026-03-24T14:13:27Z",
  "bugzilla" : {
    "description" : "NGINX: NGINX: Denial of Service via undisclosed requests when ngx_mail_auth_http_module is enabled",
    "id" : "2450791",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2450791"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-476",
  "details" : [ "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.", "A flaw was found in NGINX, specifically within the ngx_mail_auth_http_module. When this module is enabled, and CRAM-MD5 or APOP authentication is active with an authentication server that permits retries, undisclosed requests can cause NGINX worker processes to terminate. This can lead to a Denial of Service (DoS), making the affected NGINX instance unavailable to legitimate users." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2026-04-07T00:00:00Z",
    "advisory" : "RHSA-2026:6906",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.1",
    "package" : "nginx-2:1.26.3-2.el10_1.1"
  }, {
    "product_name" : "Red Hat Enterprise Linux 10.0 Extended Update Support",
    "release_date" : "2026-05-05T00:00:00Z",
    "advisory" : "RHSA-2026:13634",
    "cpe" : "cpe:/o:redhat:enterprise_linux_eus:10.0",
    "package" : "nginx-2:1.26.3-1.el10_0.8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-04-07T00:00:00Z",
    "advisory" : "RHSA-2026:6907",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8",
    "package" : "nginx:1.24-8100020260401080144.489197e6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-04-07T00:00:00Z",
    "advisory" : "RHSA-2026:6923",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "nginx:1.24-9070020260331134728.9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-04-08T00:00:00Z",
    "advisory" : "RHSA-2026:7002",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "nginx-2:1.20.1-24.el9_7.2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-04-09T00:00:00Z",
    "advisory" : "RHSA-2026:7343",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "nginx:1.26-9070020260407080353.9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions",
    "release_date" : "2026-05-11T00:00:00Z",
    "advisory" : "RHSA-2026:15942",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.0",
    "package" : "nginx-1:1.20.1-10.el9_0.3"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
    "release_date" : "2026-05-07T00:00:00Z",
    "advisory" : "RHSA-2026:14836",
    "cpe" : "cpe:/a:redhat:rhel_e4s:9.2",
    "package" : "nginx-1:1.20.1-14.el9_2.5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Extended Update Support",
    "release_date" : "2026-05-05T00:00:00Z",
    "advisory" : "RHSA-2026:13839",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.4",
    "package" : "nginx-1:1.20.1-16.el9_4.5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.4 Extended Update Support",
    "release_date" : "2026-05-11T00:00:00Z",
    "advisory" : "RHSA-2026:15943",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.4",
    "package" : "nginx:1.24-9040020260504195322.9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "release_date" : "2026-05-05T00:00:00Z",
    "advisory" : "RHSA-2026:13680",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.6",
    "package" : "nginx-2:1.20.1-22.el9_6.5"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "release_date" : "2026-05-11T00:00:00Z",
    "advisory" : "RHSA-2026:15945",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.6",
    "package" : "nginx:1.24-9060020260504194843.9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "release_date" : "2026-05-11T00:00:00Z",
    "advisory" : "RHSA-2026:15966",
    "cpe" : "cpe:/a:redhat:rhel_eus:9.6",
    "package" : "nginx:1.26-9060020260504154614.9"
  }, {
    "product_name" : "Red Hat Hardened Images",
    "release_date" : "2026-04-15T00:00:00Z",
    "advisory" : "RHSA-2026:8346",
    "cpe" : "cpe:/a:redhat:hummingbird:1",
    "package" : "nginx-main-1.30.0-1.hum1"
  }, {
    "product_name" : "Red Hat Update Infrastructure 5",
    "release_date" : "2026-04-23T00:00:00Z",
    "advisory" : "RHSA-2026:10065",
    "cpe" : "cpe:/a:redhat:rhui:5::el9",
    "package" : "rhui5/cds-rhel9:1776868774"
  }, {
    "product_name" : "Red Hat Update Infrastructure 5",
    "release_date" : "2026-04-23T00:00:00Z",
    "advisory" : "RHSA-2026:10065",
    "cpe" : "cpe:/a:redhat:rhui:5::el9",
    "package" : "rhui5/rhua-rhel9:1776868842"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-27651\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-27651\nhttps://my.f5.com/manage/s/article/K000160383" ],
  "name" : "CVE-2026-27651",
  "mitigation" : {
    "value" : "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.",
    "lang" : "en:us"
  },
  "csaw" : false
}