Summary
It was discovered that Apache HTTP Server's mod_rewrite module incorrectly
handled memory when performing certain variable lookups. A remote attacker
could possibly use this issue to cause a denial of service or execute
arbitrary code. (CVE-2026-56154)
Lucian Nitescu, Simon Kappel, and Gianluca Danesin discovered that Apache
HTTP Server's mod_http2 module incorrectly handled memory when processing
certain HTTP/2 connections. A remote attacker could possibly use this issue
to cause a denial of service or execute arbitrary code. This issue only
affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04
LTS, and Ubuntu 26.04 LTS. (CVE-2026-57941)
Juthawong Naisanguansee, Charles Vosburgh, Mike Read, and Ryoma Nishioka
discovered that Apache HTTP Server's mod_ssl module incorrectly handled
certain expressions. An attacker could possibly use this issue to bypass
intended access restrictions. (CVE-2026-59797)
Fixed packages 7
| Release | Package | Fixed in |
|---|---|---|
| Ubuntu · 22.04 LTS 22.04:LTS | apache2 | 2.4.52-1ubuntu4.24 |
| Ubuntu · 24.04 LTS 24.04:LTS | apache2 | 2.4.58-1ubuntu8.16 |
| Ubuntu · 26.04 LTS 26.04:LTS | apache2 | 2.4.66-2ubuntu2.5 |
| Ubuntu · Pro 14.04 LTS Pro:14.04:LTS | apache2 | 2.4.7-1ubuntu4.22+esm16 |
| Ubuntu · Pro 16.04 LTS Pro:16.04:LTS | apache2 | 2.4.18-2ubuntu3.17+esm21 |
| Ubuntu · Pro 18.04 LTS Pro:18.04:LTS | apache2 | 2.4.29-1ubuntu4.27+esm12 |
| Ubuntu · Pro 20.04 LTS Pro:20.04:LTS | apache2 | 2.4.41-4ubuntu3.23+esm8 |
Vulnerabilities 3
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Critical 9.8
Apache HTTP Server: mod_rewrite use-after-free via %{LA-U:HTTP:...}
Use After Free vulnerability in Apache HTTP Server's mod_rewrite when using lookahead (%{LA-U:HTTP:...}) This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.
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Critical 9.8
Apache HTTP Server: mod_http2 use-after-free / wild write via shared session->bbtmp re-entrancy
Use After Free vulnerability in Apache HTTP Server's mod_http2 via shared session->bbtmp re-entrancy This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.
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Critical 9.8
Apache HTTP Server: mod_ssl SSLRequire allows .htaccess ap_expr file-function
Improper Privilege Management vulnerability in Apache HTTP Server's mod_ssl via SSLRequire and file-related expressions. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.