--- id: CVE-2026-28780 title: >- 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 … summary: >- 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 … severity: critical cvss: 9.8 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H' cwe: - CWE-122 - CWE-787 vendor: apache product: http_server affected: - http_server < 2.4.67 patched: - http_server 2.4.67 published: '2026-05-05' updated: '2026-09-14' sourceUpdated: '2026-09-14T13:17:54.970' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28780' references: - url: 'https://httpd.apache.org/security/vulnerabilities_24.html' label: security@apache.org - url: 'http://www.openwall.com/lists/oss-security/2026/05/05/9' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://access.redhat.com/errata/RHSA-2026:21391' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:21433' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:22140' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:27200' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:27201' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:36373' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:36831' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:36846' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:47046' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:62165' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:66323' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:67152' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/security/cve/CVE-2026-28780' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2466913' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28780.json label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://www.cve.org/CVERecord?id=CVE-2026-28780' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28780' tags: - nvd - cve.org - csaf - vex - red-hat ssvc: exploitation: none automatable: 'yes' technicalImpact: total timestamp: '2026-05-06T15:49:38.049896Z' epss: 0.01631 epssPercentile: 0.75224 scores: nvd: 9.8 vendor: 8.1 adp: 9.8 ingestedAt: '2026-07-08T13:51:10.482Z' --- ## Overview 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. ## Affected - `http_server < 2.4.67` ## Remediation Upgrade past the affected range: - `http_server 2.4.67` ## Vendor advisories - **RHSA-2026:27200** · Red Hat · fixed in: Red Hat JBoss Core Services on RHEL 7 Server, Red Hat JBoss Core Services on RHEL 8 · released 2026-06-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:27200) - **RHSA-2026:47046** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-07-28 · [advisory](https://access.redhat.com/errata/RHSA-2026:47046) - **RHSA-2026:21433** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-05-27 · [advisory](https://access.redhat.com/errata/RHSA-2026:21433) - **RHSA-2026:22140** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-06-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:22140) - **RHSA-2026:36846** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.4), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) · released 2026-07-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:36846) - **RHSA-2026:36831** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream AUS (v.8.6), Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) · released 2026-07-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:36831) - **RHSA-2026:36373** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.8.8), Red Hat Enterprise Linux AppStream TUS (v.8.8) · released 2026-07-07 · [advisory](https://access.redhat.com/errata/RHSA-2026:36373) - **RHSA-2026:66323** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:66323) - **RHSA-2026:62165** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:62165) - **RHSA-2026:21391** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-05-27 · [advisory](https://access.redhat.com/errata/RHSA-2026:21391) - **RHSA-2026:27201** · Red Hat · fixed in: Red Hat JBoss Core Services 2.4.62.SP4 · released 2026-06-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:27201) - **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28780.json) - **RHSA-2026:67152** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67152)