CVE-2026-28753

LOWPre-NVD 3.73.7—
EchelonGraph scoreMEDIUM confidence

Score 3.7 from GitHub Security Advisory published 2026-03-24. a secondary CVSS source baseline 3.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
3.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 3.7Exploit: None knownExposed: 0

A fix is available — apply it.

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.

CVSS v3
3.7
EG Score
3.7(medium)
EG Risk
17(Track)
EG Risk 17/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity37% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

March 24, 2026

Last Modified

June 17, 2026

References (1)

Vendor Advisories for CVE-2026-28753(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnginx-main-1.30.0-1.hum12026-04-15redhat

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 rangeFixed inDependents
nginx—1.28.3-r0—
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
nginx—1.28.3-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
nginx—1.28.3-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
nginx1.18.0-6.1 ... 1.18.0-6.1+deb11u5 (6 versions)1.18.0-6.1+deb11u6—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
nginx1.22.1-9, 1.22.1-9+deb12u1, 1.22.1-9+deb12u2, 1.22.1-9+deb12u3, 1.22.1-9+deb12u41.22.1-9+deb12u5—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nginx1.26.3-3, 1.26.3-3+deb13u1, 1.26.3-3+deb13u21.26.3-3+deb13u3—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nginx1.26.3-3 ... 1.28.2-4 (14 versions)1.28.3-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

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.

Data Freshness Timeline

(refreshed 7× in last 7d / 29× 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.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-06 13:47 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-04 05:06 UTCEPSS rescore
  14. 2026-09-02 16:08 UTCOSV refresh
  15. 2026-09-02 14:11 UTCEPSS rescore
  16. 2026-09-01 13:53 UTCEPSS rescore
  17. 2026-09-01 04:39 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-08-30 19:17 UTCEPSS rescore
  20. 2026-08-30 01:22 UTCEPSS rescore
  21. 2026-08-28 21:41 UTCEPSS rescore
  22. 2026-08-27 14:25 UTCEPSS rescore
  23. 2026-08-26 14:46 UTCEPSS rescore
  24. 2026-08-25 13:49 UTCEPSS rescore
  25. 2026-08-24 14:17 UTCEPSS rescore
Show 44 more
  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-19 17:03 UTCEPSS rescore
  6. 2026-08-18 13:48 UTCEPSS rescore
  7. 2026-08-17 13:47 UTCEPSS rescore
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 10:39 UTCEG score recompute
  10. 2026-08-16 10:39 UTCVendor advisory
  11. 2026-08-16 10:39 UTCGHSA enrichment
  12. 2026-08-16 02:14 UTCEPSS rescore
  13. 2026-08-15 01:30 UTCEPSS rescore
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-12 21:30 UTCEG score recompute
  16. 2026-08-12 21:30 UTCVendor advisory
  17. 2026-08-12 21:30 UTCGHSA enrichment
  18. 2026-08-12 13:50 UTCEPSS rescore
  19. 2026-08-11 13:42 UTCEPSS rescore
  20. 2026-08-11 00:00 UTCEPSS rescore
  21. 2026-08-09 13:46 UTCEPSS rescore
  22. 2026-08-09 06:27 UTCEG score recompute
  23. 2026-08-09 06:27 UTCVendor advisory
  24. 2026-08-09 06:27 UTCGHSA enrichment
  25. 2026-08-08 16:37 UTCEPSS rescore
  26. 2026-08-06 13:46 UTCEPSS rescore
  27. 2026-08-06 01:12 UTCEG score recompute
  28. 2026-08-06 01:12 UTCVendor advisory
  29. 2026-08-06 01:12 UTCGHSA enrichment
  30. 2026-08-05 19:17 UTCEPSS rescore
  31. 2026-08-04 15:10 UTCEPSS rescore
  32. 2026-08-03 10:36 UTCEPSS rescore
  33. 2026-08-02 15:45 UTCEG score recompute
  34. 2026-08-02 15:45 UTCVendor advisory
  35. 2026-08-02 15:45 UTCGHSA enrichment
  36. 2026-08-02 02:26 UTCEPSS rescore
  37. 2026-08-01 04:16 UTCEPSS rescore
  38. 2026-07-30 16:27 UTCEPSS rescore
  39. 2026-07-30 01:30 UTCEPSS rescore
  40. 2026-07-28 15:36 UTCEPSS rescore
  41. 2026-07-27 12:50 UTCEG score recompute
  42. 2026-07-27 12:50 UTCVendor advisory
  43. 2026-07-27 12:50 UTCGHSA enrichment
  44. 2026-07-27 12:50 UTCOSV refresh

Frequently asked(5)

What is CVE-2026-28753?
CVE-2026-28753 is a low vulnerability published on March 24, 2026. NGINX Plus and NGINX Open Source have a vulnerability in the ngxmailsmtp_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.…
When was CVE-2026-28753 disclosed?
CVE-2026-28753 was first published in the National Vulnerability Database on March 24, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28753 actively exploited?
CVE-2026-28753 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.3% of all scored CVEs.
What is the CVSS score of CVE-2026-28753?
CVE-2026-28753 has a CVSS v3 base score of 3.7 (NVD).
How do I remediate CVE-2026-28753?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28753, 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

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