CVE-2026-28780
📛 CVE Title
Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header()
Description
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.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- apache
- CVSS severity
- critical
- CVSS score
- 9.8 / 10
- CVSS vector
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Effective score
- 9.8 / 10 CRITICAL source: CNA overview
- CWE(s)
-
CWE-122 - Reserved
- 2026-03-03
- Published
- 2026-05-05 23:29 UTC
- Last updated
- 2026-05-06 17:50 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/28xxx/CVE-2026-28780.json
- Linked Threat
- CVE-2026-28780 — CVE-2026-28780
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-05-05 22:16:00 UTC
- NVD last modified
- 2026-05-06 20:31:10 UTC
- NVD CVSS v3.1
- 9.8 / 10 CRITICAL source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 5.9 / 10
- EPSS score
- 0.0003 (probability of exploitation in next 30 days)
- EPSS percentile
- 7.76% vs all CVEs — higher = more likely to be exploited, as of 2026-05-25
NVD / KEV / EPSS data refreshed 2026-05-25 17:26 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
European Union Vulnerability Database ENISA EUVD
ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.
- EUVD ID
-
EUVD-2026-27506 - Assigner
- apache
- Published
- May 5, 2026, 9:29:41 PM
- Updated
- May 6, 2026, 3:50:18 PM
- EUVD base score (CVSS 3.1)
-
9.8 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EUVD-reported EPSS
- 0.0300
- Vendors
- Apache Software Foundation
- Products
-
Apache HTTP Server (0 ≤2.4.66)
ENISA description: 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.
EUVD references (1)
Affected products (1)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server |
0 (affected)
|
— |
Affected products — CPE 2.3 (1) NVD
NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.
cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
Vendor references (1)
References embedded in the original CVE record by the assigning CNA.
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory
MITRE references (1) cveawg.mitre.org
Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory
Web references (9)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
- https://attackerkb.com/topics/CVE-2026-28780 rapid7:attackerkb.com
- https://security.alpinelinux.org/vuln/CVE-2026-28780 rapid7:security.alpinelinux.org
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-27506 rapid7:euvd.enisa.europa.eu
- http://cwe.mitre.org/data/definitions/122.html rapid7:cwe.mitre.org
- https://www.first.org/epss/ tenable:www.first.org
- https://www.securityweek.com/critical-high-severity-vulnerabilities-patched-in-apache-mina-http-server/ tenable:www.securityweek.com
- http://www.openwall.com/lists/oss-security/2026/05/05/9 tenable:www.openwall.com
- https://nvd.nist.gov/vuln/detail/CVE-2026-28780 tenable:nvd.nist.gov
- https://www.cve.org/CVERecord?id=CVE-2026-28780 tenable:www.cve.org
NVD-tagged references (2)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- http://www.openwall.com/lists/oss-security/2026/05/05/9 af854a3a-2127-422b-91ae-364da2661108 Mailing ListThird Party Advisory
- https://httpd.apache.org/security/vulnerabilities_24.html security@apache.org Release NotesVendor Advisory
Remediations (17)
Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.
-
web:learn.microsoft.com
January 2026 Security Updates This release consists of the following 112 Microsoft CVEs : Tag CVE Base Score CVSS Vector Exploitability FAQs? Workarounds? Mitigations ? Windows Deployment Services CVE - 2026 -0386 SQL Server CVE - 2026 -20803 Windows Hello…
2026-05-23 21:13 UTC -
web:portal.msrc.microsoft.com
The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.
2026-05-23 21:13 UTC -
web:securityvulnerability.io
Explore a heap-based buffer overflow vulnerability affecting Apache HTTP Server's mod_proxy_ajp. Learn more about CVE-2026-28780 .
2026-05-23 21:13 UTC -
web:ubuntu.com
Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things.
2026-05-23 21:13 UTC -
web:www.bleepingcomputer.com
Today is Microsoft's March 2026 Patch Tuesday with security updates for 79 flaws, including 2 publicly disclosed zero-day vulnerabilities.
2026-05-23 21:13 UTC -
web:www.crowdstrike.com
Microsoft has released security updates for 114 vulnerabilities, including three zero-days, plus eight critical CVEs in its January 2026 Patch Tuesday rollout.
2026-05-23 21:13 UTC -
web:www.cve.news
CVE-2026-28780 is a heap-based buffer overflow vulnerability discovered in the mod_proxy_ajp module of the Apache HTTP Server. This vulnerability is present in all versions up to and including Apache HTTP Server 2.4.66.
2026-05-23 21:13 UTC -
web:www.suse.com
Secure your Linux systems from CVE-2026-28780 . Stay ahead of potential threats with the latest security updates from SUSE.
2026-05-23 21:13 UTC -
web:www.tenable.com
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. ...
2026-05-23 21:13 UTC -
web:www.thehackerwire.com
How severe is CVE-2026-28780 ? What Apache products are affected by CVE-2026-28780 ? How do I fix or mitigate CVE-2026-28780 ? When was CVE-2026-28780 disclosed?
2026-05-23 21:13 UTC -
web:access.redhat.com
Learn about our open source products, services, and company. You are here
2026-05-26 02:46 UTC -
web:blog.qualys.com
With Qualys Policy Audit's out-of-the-box mitigation or Compensatory Controls, which reduce the risk of a vulnerability being exploited because the remediation ( fix / patch ) cannot be done immediately, these security controls are not recommended by any industry standards, such as CIS and DISA-STIG.
2026-05-26 02:46 UTC -
web:github.com
GitHub is where people build software. More than 150 million people use GitHub to discover, fork, and contribute to over 420 million projects.
2026-05-26 02:46 UTC -
web:msrc.microsoft.com
The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.
2026-05-26 02:46 UTC -
web:nvd.nist.gov
An official website of the United States government Here's how you know
2026-05-26 02:46 UTC -
web:www.oracle.com
This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.
2026-05-26 02:46 UTC -
web:zecurit.com
Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .
2026-05-26 02:46 UTC
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-28780.json.
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