CVE-2026-23411: Linux kernel · apparmor: fix race between freeing data and fs accessing it
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 4.15.0-1200.215~14.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.15.0-1200.215~14.04.1, 4.15.0-1191.204~16.04.1, 4.15.0-1200.215~16.04.1 +108
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-19.19?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1010.10?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1009.9?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: apparmor: fix race between freeing data and fs accessing it AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can aand does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction.
References
- ubuntu.com/security/CVE-2026-23411 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23411 (opens in a new tab)
- ubuntu.com/blog/apparmor-vulnerability-fixes-available (opens in a new tab)
- ubuntu.com/security/vulnerabilities/crackarmor (opens in a new tab)
- cdn2.qualys.com/advisory/2026/03/10/crack-armor.txt (opens in a new tab)
- openwall.com/lists/oss-security/2026/04/01/3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8152-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8164-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8165-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8163-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8098-10 (opens in a new tab)
- ubuntu.com/security/notices/USN-8201-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8224-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8243-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8261-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8266-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8267-1 (opens in a new tab)