CVE-2026-28780

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-06. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

Heap-based Buffer Overflow vulnerability in mod_proxy_ajp of Apache HTTP Server. If mod_proxy_ajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to mod_proxy_ajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
—
EPSS
69.2%
KEV
Not listed

Published

May 5, 2026

Last Modified

July 15, 2026

Advisory Details (13)

Auto-updated Jul 16, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support

https://access.redhat.com/errata/RHSA-2026:36846
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.6 Extended Update Support

https://access.redhat.com/errata/RHSA-2026:36831
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Serv

https://access.redhat.com/errata/RHSA-2026:36373
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:27201
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:27200
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:22140
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:21433
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:21391
generic

oss-security - CVE-2026-28780: Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header()

http://www.openwall.com/lists/oss-security/2026/05/05/9
generic Patch Available🔴 Active Exploitation

Apache HTTP Server 2.4 vulnerabilities - The Apache HTTP Server Project

https://httpd.apache.org/security/vulnerabilities_24.html
redhat Patch Available

2466913 – (CVE-2026-28780) CVE-2026-28780 Apache HTTP Server: mod_proxy_ajp: Apache HTTP Server mod_proxy_ajp: Arbitrary code execution via heap-based buffer overflow

Affected: Red Hat Enterprise Linux 9

https://bugzilla.redhat.com/show_bug.cgi?id=2466913
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-28780
redhat Patch Available

Affected: Red Hat Enterprise Linux 6",

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28780.json

Vendor Advisories for CVE-2026-28780(9)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuapache2-utils (2.4.18-2ubuntu3.17+esm18) @ xenial2026-06-15ubuntu
ubuntuapache2-utils (2.4.66-2ubuntu2.1) @ resolute2026-06-15ubuntu
redhathttpd:2.4-8100020260519200905.489197e62026-06-01redhat
redhathttpd-0:2.4.63-13.el10_2.12026-05-27redhat
redhathttpd-0:2.4.62-13.el9_8.12026-05-27redhat

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(2)

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

Additional Vendor Advisories

(2)

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 14× in last 7d / 47× 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.

Showing the most recent 100 of 274 total refreshes for this CVE.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-21 15:24 UTCEPSS rescore
  5. 2026-07-20 19:02 UTCOSV refresh
  6. 2026-07-20 17:08 UTCEPSS rescore
  7. 2026-07-20 17:08 UTCEPSS rescore
  8. 2026-07-19 14:31 UTCEPSS rescore
  9. 2026-07-19 14:31 UTCEPSS rescore
  10. 2026-07-19 02:29 UTCEPSS rescore
  11. 2026-07-18 10:04 UTCEPSS rescore
  12. 2026-07-18 10:04 UTCEPSS rescore
  13. 2026-07-16 17:03 UTCEPSS rescore
  14. 2026-07-16 17:03 UTCEPSS rescore
  15. 2026-07-15 16:57 UTCEPSS rescore
  16. 2026-07-15 16:57 UTCEPSS rescore
  17. 2026-07-15 02:00 UTCEPSS rescore
  18. 2026-07-15 02:00 UTCEPSS rescore
  19. 2026-07-13 22:30 UTCEPSS rescore
  20. 2026-07-13 06:13 UTCEPSS rescore
  21. 2026-07-13 06:13 UTCEPSS rescore
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 08:27 UTCEPSS rescore
  24. 2026-07-09 19:10 UTCEPSS rescore
  25. 2026-07-08 15:15 UTCEPSS rescore
Show 75 more
  1. 2026-07-07 13:46 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-05 02:30 UTCEPSS rescore
  7. 2026-07-04 06:31 UTCEPSS rescore
  8. 2026-07-01 15:06 UTCEPSS rescore
  9. 2026-06-30 23:22 UTCEPSS rescore
  10. 2026-06-30 23:22 UTCEPSS rescore
  11. 2026-06-29 14:06 UTCEPSS rescore
  12. 2026-06-28 14:07 UTCEPSS rescore
  13. 2026-06-28 14:07 UTCEPSS rescore
  14. 2026-06-28 04:56 UTCEPSS rescore
  15. 2026-06-28 04:56 UTCEPSS rescore
  16. 2026-06-27 03:08 UTCEPSS rescore
  17. 2026-06-25 13:49 UTCEPSS rescore
  18. 2026-06-25 13:49 UTCEPSS rescore
  19. 2026-06-24 14:05 UTCEPSS rescore
  20. 2026-06-24 14:05 UTCEPSS rescore
  21. 2026-06-23 21:33 UTCEPSS rescore
  22. 2026-06-23 21:32 UTCEPSS rescore
  23. 2026-06-22 14:25 UTCEPSS rescore
  24. 2026-06-22 14:25 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
  26. 2026-06-21 14:56 UTCEPSS rescore
  27. 2026-06-21 01:59 UTCEPSS rescore
  28. 2026-06-21 01:59 UTCEPSS rescore
  29. 2026-06-19 19:25 UTCEPSS rescore
  30. 2026-06-19 19:25 UTCEPSS rescore
  31. 2026-06-18 17:52 UTCEPSS rescore
  32. 2026-06-17 17:53 UTCEPSS rescore
  33. 2026-06-17 17:53 UTCEPSS rescore
  34. 2026-06-16 17:52 UTCEPSS rescore
  35. 2026-06-15 17:48 UTCEPSS rescore
  36. 2026-06-15 04:15 UTCVendor advisory
  37. 2026-06-15 04:15 UTCGHSA enrichment
  38. 2026-06-15 00:13 UTCVendor advisory
  39. 2026-06-15 00:13 UTCGHSA enrichment
  40. 2026-06-14 23:18 UTCEPSS rescore
  41. 2026-06-14 19:57 UTCVendor advisory
  42. 2026-06-14 19:57 UTCGHSA enrichment
  43. 2026-06-14 15:56 UTCVendor advisory
  44. 2026-06-14 15:56 UTCGHSA enrichment
  45. 2026-06-14 11:47 UTCVendor advisory
  46. 2026-06-14 11:47 UTCGHSA enrichment
  47. 2026-06-14 07:48 UTCVendor advisory
  48. 2026-06-14 07:48 UTCGHSA enrichment
  49. 2026-06-13 23:00 UTCEPSS rescore
  50. 2026-06-13 01:38 UTCVendor advisory
  51. 2026-06-13 01:38 UTCGHSA enrichment
  52. 2026-06-12 23:12 UTCEPSS rescore
  53. 2026-06-12 23:12 UTCEPSS rescore
  54. 2026-06-12 10:07 UTCVendor advisory
  55. 2026-06-12 10:07 UTCGHSA enrichment
  56. 2026-06-12 05:17 UTCVendor advisory
  57. 2026-06-12 05:17 UTCGHSA enrichment
  58. 2026-06-12 01:16 UTCVendor advisory
  59. 2026-06-12 01:16 UTCGHSA enrichment
  60. 2026-06-11 21:17 UTCVendor advisory
  61. 2026-06-11 21:17 UTCGHSA enrichment
  62. 2026-06-11 17:18 UTCVendor advisory
  63. 2026-06-11 17:18 UTCGHSA enrichment
  64. 2026-06-11 14:00 UTCEPSS rescore
  65. 2026-06-11 11:21 UTCVendor advisory
  66. 2026-06-11 11:21 UTCGHSA enrichment
  67. 2026-06-11 07:20 UTCVendor advisory
  68. 2026-06-11 07:20 UTCGHSA enrichment
  69. 2026-06-11 03:21 UTCVendor advisory
  70. 2026-06-11 03:21 UTCGHSA enrichment
  71. 2026-06-10 23:22 UTCVendor advisory
  72. 2026-06-10 23:22 UTCGHSA enrichment
  73. 2026-06-10 22:18 UTCEPSS rescore
  74. 2026-06-10 22:18 UTCEPSS rescore
  75. 2026-06-10 19:23 UTCVendor advisory

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-28780?
CVE-2026-28780 is a critical vulnerability published on May 5, 2026. Heap-based Buffer Overflow vulnerability in modproxyajp of Apache HTTP Server. If modproxyajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to modproxyajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer. This issue…
When was CVE-2026-28780 disclosed?
CVE-2026-28780 was first published in the National Vulnerability Database on May 5, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-28780 actively exploited?
CVE-2026-28780 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 69.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-28780?
CVE-2026-28780 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-28780?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-28780, 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.

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