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.
CVE-2026-27651
HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence
Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-03-24. the CNA's CVSS baseline 7.5; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: cna:github_m, ghsa
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 56.1%
- KEV
- Not listed
Published
March 24, 2026
Last Modified
June 30, 2026
Advisory Details (10)
Auto-updated Jul 3, 2026Patch available. Sources: redhat.
redhat Patch Available
Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:15966redhat Patch Available
Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:15945redhat Patch Available
Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:15943redhat Patch Available
Affected: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions.
https://access.redhat.com/errata/RHSA-2026:15942redhat Patch Available
Affected: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions.
https://access.redhat.com/errata/RHSA-2026:14836redhat Patch Available
Affected: Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions.
https://access.redhat.com/errata/RHSA-2026:13839redhat Patch Available
Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:13680redhat Patch Available
Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.
https://access.redhat.com/errata/RHSA-2026:13634redhat Patch Available
Vendor Advisories for CVE-2026-27651(7)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2026-27651Microsoft Security Response Center (MSRC)High
NGINX ngx_mail_auth_http_module vulnerability
- RHSA-2026:13680Red Hat Product SecurityHigh
Red Hat Security Advisory: nginx security update
- RHSA-2026:10065Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Update Infrastructure 5.1 security update
- RHSA-2026:8346Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
- RHSA-2026:7002Red Hat Product SecurityHigh
Red Hat Security Advisory: nginx security update
- RHSA-2026:6906Red Hat Product SecurityHigh
Red Hat Security Advisory: nginx security update
- GHSA-82w2-x7hf-5h8rGitHub Security AdvisoriesHigh
When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source,...
Patch Availability(16)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | nginx-light (1.10.3-0ubuntu0.16.04.5+esm7) @ xenial | 2026-06-30 | ubuntu |
| redhat | nginx:1.24-9040020260504195322.9 | 2026-05-11 | redhat |
| redhat | nginx:1.26-9060020260504154614.9 | 2026-05-11 | redhat |
| redhat | nginx:1.24-9060020260504194843.9 | 2026-05-11 | redhat |
| redhat | nginx-1:1.20.1-10.el9_0.3 | 2026-05-11 | redhat |
| redhat | nginx-1:1.20.1-14.el9_2.5 | 2026-05-07 | redhat |
| redhat | nginx-2:1.20.1-22.el9_6.5 | 2026-05-05 | redhat |
| redhat | nginx-2:1.26.3-1.el10_0.8 | 2026-05-05 | redhat |
| redhat | nginx-1:1.20.1-16.el9_4.5 | 2026-05-05 | redhat |
| redhat | rhui5/rhua-rhel9:1776868842 | 2026-04-23 | redhat |
| redhat | nginx-main-1.30.0-1.hum1 | 2026-04-15 | redhat |
| redhat | nginx:1.26-9070020260407080353.9 | 2026-04-09 | redhat |
| redhat | nginx-2:1.20.1-24.el9_7.2 | 2026-04-08 | redhat |
| redhat | nginx:1.24-8100020260401080144.489197e6 | 2026-04-07 | redhat |
| redhat | nginx:1.24-9070020260331134728.9 | 2026-04-07 | redhat |
| redhat | nginx-2:1.26.3-2.el10_1.1 | 2026-04-07 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(11)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
- Red HatRHSA-2026:13634IMPORTANT2026-03-24
RHSA-2026:13634 — Important
- Red HatRHSA-2026:13839IMPORTANT2026-03-24
RHSA-2026:13839 — Important
- Red HatRHSA-2026:14836IMPORTANT2026-03-24
RHSA-2026:14836 — Important
- Red HatRHSA-2026:15942IMPORTANT2026-03-24
RHSA-2026:15942 — Important
- Red HatRHSA-2026:15943IMPORTANT2026-03-24
RHSA-2026:15943 — Important
- Red HatRHSA-2026:15945IMPORTANT2026-03-24
RHSA-2026:15945 — Important
- Red HatRHSA-2026:15966IMPORTANT2026-03-24
RHSA-2026:15966 — Important
- Red HatRHSA-2026:6907IMPORTANT2026-03-24
RHSA-2026:6907 — Important
- Red HatRHSA-2026:6923IMPORTANT2026-03-24
RHSA-2026:6923 — Important
- Red HatRHSA-2026:7343IMPORTANT2026-03-24
RHSA-2026:7343 — Important
- UbuntuUSN-8375-1MEDIUM
nginx vulnerabilities
Data Freshness Timeline
(refreshed 8× in last 7d / 23× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-30 04:32 UTCNVD updateCVSS v4 → 8.7
- 2026-06-30 04:31 UTCEG score recompute
- 2026-06-30 04:31 UTCVendor advisory
- 2026-06-30 04:31 UTCGHSA enrichment
Related CVEs(same vendor + same CWE)
Same vendor
10 shownmsrc · redhat
Frequently asked(5)
What is CVE-2026-27651?
CVE-2026-27651 is a high vulnerability published on March 24, 2026. When the ngxmailauthhttpmodule 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…
When was CVE-2026-27651 disclosed?
CVE-2026-27651 was first published in the National Vulnerability Database on March 24, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27651 actively exploited?
CVE-2026-27651 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 56.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-27651?
CVE-2026-27651 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-27651?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27651, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-27651
Is Your Infrastructure Affected by CVE-2026-27651?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.