CVE-2026-27651

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-03-24. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.7%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.9% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
1.7%
EPSS %ILE
76th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.7% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

March 24, 2026

Last Modified

July 15, 2026

Advisory Details (10)

Auto-updated Jul 3, 2026
Patch available. Sources: redhat.
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:15966
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:15945
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.4 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:15943
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:15942
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:14836
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions.

https://access.redhat.com/errata/RHSA-2026:13839
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 9.6 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:13680
Red HatMentions a patch (unverified)

Affected: Red Hat Enterprise Linux 10.0 Extended Update Support.

https://access.redhat.com/errata/RHSA-2026:13634
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:10065

Patch Availability(16)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntunginx-light (1.10.3-0ubuntu0.16.04.5+esm7) @ xenial2026-06-30ubuntu
redhatnginx:1.24-9040020260504195322.92026-05-11redhat
redhatnginx:1.26-9060020260504154614.92026-05-11redhat
redhatnginx:1.24-9060020260504194843.92026-05-11redhat
redhatnginx-1:1.20.1-10.el9_0.32026-05-11redhat
redhatnginx-1:1.20.1-14.el9_2.52026-05-07redhat
redhatnginx-2:1.20.1-22.el9_6.52026-05-05redhat
redhatnginx-2:1.26.3-1.el10_0.82026-05-05redhat
redhatnginx-1:1.20.1-16.el9_4.52026-05-05redhat
redhatrhui5/rhua-rhel9:17768688422026-04-23redhat
redhatnginx-main-1.30.0-1.hum12026-04-15redhat
redhatnginx:1.26-9070020260407080353.92026-04-09redhat
redhatnginx-2:1.20.1-24.el9_7.22026-04-08redhat
redhatnginx:1.24-8100020260401080144.489197e62026-04-07redhat
redhatnginx:1.24-9070020260331134728.92026-04-07redhat
redhatnginx-2:1.26.3-2.el10_1.12026-04-07redhat

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.

Affected Packages

(7 across 7 ecosystems)
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.28.3-r0: fixed in 1.28.3-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.28.3-r0: fixed in 1.28.3-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
nginx—
  • every version up to 1.28.3-r0: fixed in 1.28.3-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.18.0-6.1 ... 1.18.0-6.1+deb11u5 (6 versions)
  • every version up to 1.18.0-6.1+deb11u6: fixed in 1.18.0-6.1+deb11u6
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.22.1-9, 1.22.1-9+deb12u1, 1.22.1-9+deb12u2, 1.22.1-9+deb12u3, 1.22.1-9+deb12u4
  • every version up to 1.22.1-9+deb12u5: fixed in 1.22.1-9+deb12u5
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.26.3-3, 1.26.3-3+deb13u1, 1.26.3-3+deb13u2
  • every version up to 1.26.3-3+deb13u3: fixed in 1.26.3-3+deb13u3
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
nginx1.26.3-3 ... 1.28.2-4 (14 versions)
  • every version up to 1.28.3-1: fixed in 1.28.3-1
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(11)

Data Freshness Timeline

(refreshed 11× in last 7d / 33× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 97 of 169 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 72 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:31 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  2. 2026-10-18 16:31 UTCEPSS rescoreEPSS 1.7% · 76th percentile
  3. 2026-10-18 03:51 UTCEG score recompute
  4. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  5. 2026-10-17 16:25 UTCEG score recompute
  6. 2026-10-17 16:25 UTCVendor advisory
  7. 2026-10-17 16:25 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  8. 2026-10-16 16:41 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  9. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  10. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.9% · 60th percentile
  11. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  12. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  13. 2026-10-12 16:17 UTCEG score recompute
  14. 2026-10-11 19:59 UTCEG score recompute
  15. 2026-10-11 17:13 UTCEG score recompute
  16. 2026-10-11 14:44 UTCEG score recompute
  17. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  18. 2026-10-11 06:25 UTCOSV refresh
  19. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  20. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  21. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  22. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  23. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  24. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  25. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.9% · 59th percentile
Show 72 more
  1. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  2. 2026-10-01 19:49 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  3. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  4. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  5. 2026-09-26 15:58 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  6. 2026-09-26 00:26 UTCEPSS rescoreEPSS 1.1% · 63rd percentile
  7. 2026-09-21 18:49 UTCOSV refresh
  8. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  9. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  10. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  11. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.9% · 59th percentile
  12. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  13. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  14. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  15. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  16. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  17. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  18. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  19. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  20. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  21. 2026-09-02 15:38 UTCOSV refresh
  22. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  23. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  24. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  25. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  26. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  27. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  28. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  29. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  30. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  31. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  32. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  33. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  34. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.9% · 58th percentile
  35. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  36. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  37. 2026-08-16 10:38 UTCEG score recompute
  38. 2026-08-16 10:38 UTCVendor advisory
  39. 2026-08-16 10:38 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  40. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  41. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  42. 2026-08-14 19:41 UTCVendor advisory
  43. 2026-08-14 19:41 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  44. 2026-08-14 06:51 UTCEG score recompute
  45. 2026-08-14 06:51 UTCVendor advisory
  46. 2026-08-14 06:51 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  47. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  48. 2026-08-12 21:30 UTCEG score recompute
  49. 2026-08-12 21:30 UTCVendor advisory
  50. 2026-08-12 21:30 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  51. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  52. 2026-08-11 21:08 UTCEG score recompute
  53. 2026-08-11 21:08 UTCVendor advisory
  54. 2026-08-11 21:08 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  55. 2026-08-11 13:42 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  56. 2026-08-11 04:10 UTCEG score recompute
  57. 2026-08-11 04:10 UTCVendor advisory
  58. 2026-08-11 04:10 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  59. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  60. 2026-08-10 05:27 UTCVendor advisory
  61. 2026-08-10 05:27 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  62. 2026-08-09 17:57 UTCEG score recompute
  63. 2026-08-09 17:57 UTCVendor advisory
  64. 2026-08-09 17:57 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  65. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  66. 2026-08-09 06:27 UTCEG score recompute
  67. 2026-08-09 06:27 UTCVendor advisory
  68. 2026-08-09 06:27 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  69. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.9% · 57th percentile
  70. 2026-08-08 04:17 UTCVendor advisory
  71. 2026-08-08 04:17 UTCGHSA enrichmentGHSA-82w2-x7hf-5h8r · GitHub severity HIGH · GitHub CVSS 7.5
  72. 2026-08-07 16:47 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-27651?
CVE-2026-27651 is a high-severity vulnerability; its CVE record was 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 made public?
CVE-2026-27651 was made public on March 24, 2026: that is the date its CVE record's CNA, F5, Inc., gives for when the vulnerability was made public. The CVE record itself was published on March 24, 2026. EchelonGraph's copy of the record carries a last-modified date of July 15, 2026; the record at its source may have been updated since.
Is CVE-2026-27651 actively exploited?
CVE-2026-27651 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.7% probability of exploitation in the next 30 days (76th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-27651?
CVE-2026-27651 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-27651?
A fix for CVE-2026-27651 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-27651 are linked in the Vendor Advisories panel on this page.

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