Apache2: Use After Free vulnerability
Affects apache2Source GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 2.4.29-1ubuntu4.27+esm12 : patch apache2 as a priority.
Data as of 10 Nov 2026, 06:10 UTC
- Patch
- Available – fixed in 2.4.29-1ubuntu4.27+esm12, 2.4.41-4ubuntu3.23+esm8, 2.4.52-1ubuntu4.24 +2
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
Apply the official security patches provided by Ubuntu as listed in the security notice USN-8898-1. The fixed versions are 2.4.29-1ubuntu4.27+esm12, 2.4.41-4ubuntu3.23+esm8, 2.4.52-1ubuntu4.24, 2.4.58-1ubuntu8.16, and 2.4.66-2ubuntu2.5. No additional mitigation is required beyond updating to these patched versions.
Description
A critical use-after-free vulnerability exists in Apache HTTP Server's mod_http2 module due to shared session->bbtmp re-entrancy. This affects Apache HTTP Server versions from 2.4.0 through specific Ubuntu package versions prior to fixed releases. The flaw allows remote attackers to cause high impact including full confidentiality, integrity, and availability compromise. Patches are available and should be applied promptly.
References
- ubuntu.com/security/CVE-2026-57941 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-57941 (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/2026/10/01/19 (opens in a new tab)
- ubuntu.com/security/notices/USN-8898-1 (opens in a new tab)