Apache2: Use After Free vulnerability
Affects apache2Source GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 2.4.7-1ubuntu4.22+esm16 : patch apache2 as a priority.
Data as of 10 Nov 2026, 06:10 UTC
- Patch
- Available – fixed in 2.4.7-1ubuntu4.22+esm16, 2.4.18-2ubuntu3.17+esm21, 2.4.29-1ubuntu4.27+esm12 +4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10apache2pkg:deb/ubuntu/apache2?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSapache2pkg:deb/ubuntu/apache2?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSapache2pkg:deb/ubuntu/apache2?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSapache2pkg:deb/ubuntu/apache2?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu Pro 20.04 LTSapache2pkg:deb/ubuntu/apache2?arch=source&distro=esm-infra/focalOther threats | Affected
| Fixed in
|
Ubuntu Pro 18.04 LTSapache2pkg:deb/ubuntu/apache2?arch=source&distro=esm-infra/bionicOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied immediately. Ubuntu has released fixed package versions for all affected LTS releases, including 14.04 through 26.04. After applying updates, a restart of the apache2 service is required to complete remediation. Users should follow the official Ubuntu security notice USN-8898-1 for detailed update instructions. No additional mitigations are specified or required beyond applying the official patches.
Description
A use-after-free vulnerability exists in the Apache HTTP Server's mod_rewrite module when using lookahead expressions (%{LA-U:HTTP:...}). This flaw affects Apache HTTP Server versions from 2.4.0 through 2.4.68. Exploitation could allow a remote attacker to cause denial of service or execute arbitrary code. Fixes have been released for multiple Ubuntu package versions, and users are advised to update and restart Apache to apply the patches.
References
- ubuntu.com/security/CVE-2026-56154 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-56154 (opens in a new tab)
- httpd.apache.org/security/vulnerabilities_24.html (opens in a new tab)
- httpd.apache.org/security/vulnerabilities_24.html (opens in a new tab)
- openwall.com/lists/oss-security/2026/10/01/17 (opens in a new tab)
- ubuntu.com/security/notices/USN-8898-1 (opens in a new tab)