CVE & CISA-KEV Catalog

CVE-2026-23404

MEDIUM
5.5
CVSS v3
NVD

Description

In the Linux kernel, the following vulnerability has been resolved: apparmor: replace recursive profile removal with iterative approach The profile removal code uses recursion when removing nested profiles, which can lead to kernel stack exhaustion and system crashes. Reproducer: $ pf='a'; for ((i=0; i<1024; i++)); do echo -e "profile $pf { \n }" | apparmor_parser -K -a; pf="$pf//x"; done $ echo -n a > /sys/kernel/security/apparmor/.remove Replace the recursive __aa_profile_list_release() approach with an iterative approach in __remove_profile(). The function repeatedly finds and removes leaf profiles until the entire subtree is removed, maintaining the same removal semantic without recursion.

How to fix

Remediation Available
linuxDebian
Fixed in:5.10.251-1CVE-2026-23404
Fixed in:6.1.164-1CVE-2026-23404
Fixed in:6.12.74-2CVE-2026-23404
Fixed in:6.19.6-2CVE-2026-23404
linuxUbuntu
Fixed in:4.15.0-249.261USN-8266-1
linux-awsUbuntu
Fixed in:4.15.0-1191.204USN-8266-1
linux-aws-fipsUbuntu
Fixed in:4.15.0-2129.135USN-8266-1
linux-aws-hweUbuntu
Fixed in:4.15.0-1191.204~16.04.1USN-8266-1
linux-azureUbuntu
Fixed in:4.15.0-1200.215~16.04.1USN-8267-1
Fixed in:5.15.0-1109.118USN-8163-2
linux-azure-4.15Ubuntu
Fixed in:4.15.0-1200.215USN-8266-1
linux-azure-5.15Ubuntu
Fixed in:5.15.0-1110.119~20.04.1USN-8243-1
linux-azure-5.4Ubuntu
Fixed in:5.4.0-1161.167~18.04.1USN-8201-1
linux-azure-fipsUbuntu
Fixed in:4.15.0-2109.115USN-8267-1
Fixed in:5.15.0-1109.118+fips1USN-8163-1
Fixed in:6.8.0-1052.58+fips1USN-8165-1
linux-bluefieldUbuntu
Fixed in:5.4.0-1116.123USN-8224-1
linux-fipsUbuntu
Fixed in:4.15.0-1146.158USN-8266-1
linux-gcpUbuntu
Fixed in:4.15.0-1184.201~16.04.1USN-8266-1
linux-gcp-4.15Ubuntu
Fixed in:4.15.0-1184.201USN-8266-1
linux-gcp-fipsUbuntu
Fixed in:4.15.0-2092.98USN-8266-1
linux-hweUbuntu
Fixed in:4.15.0-249.261~16.04.1USN-8266-1
linux-image-4.15.0-1146-fipsUbuntu
Fixed in:4.15.0-1146.158USN-8266-1
linux-image-4.15.0-1153-oracleUbuntu
Fixed in:4.15.0-1153.164~16.04.1USN-8267-1
Fixed in:4.15.0-1153.164USN-8266-1
linux-image-4.15.0-1173-kvmUbuntu
Fixed in:4.15.0-1173.178USN-8266-1
linux-image-4.15.0-1184-gcpUbuntu
Fixed in:4.15.0-1184.201~16.04.1USN-8266-1
Fixed in:4.15.0-1184.201USN-8266-1
linux-image-4.15.0-1191-awsUbuntu
Fixed in:4.15.0-1191.204~16.04.1USN-8266-1
Fixed in:4.15.0-1191.204USN-8266-1
linux-image-4.15.0-1200-azureUbuntu
Fixed in:4.15.0-1200.215~16.04.1USN-8267-1
Fixed in:4.15.0-1200.215USN-8266-1
linux-image-4.15.0-2092-gcp-fipsUbuntu
Fixed in:4.15.0-2092.98USN-8266-1
linux-image-4.15.0-2109-azure-fipsUbuntu
Fixed in:4.15.0-2109.115USN-8267-1
linux-image-4.15.0-2129-aws-fipsUbuntu
Fixed in:4.15.0-2129.135USN-8266-1
linux-image-4.15.0-249-genericUbuntu
Fixed in:4.15.0-249.261~16.04.1USN-8266-1
Fixed in:4.15.0-249.261USN-8266-1
linux-image-4.15.0-249-lowlatencyUbuntu
Fixed in:4.15.0-249.261~16.04.1USN-8266-1
Fixed in:4.15.0-249.261USN-8266-1
linux-image-5.15.0-1096-intel-iot-realtimeUbuntu
Fixed in:5.15.0-1096.98USN-8164-1
linux-image-5.15.0-1109-azureUbuntu
Fixed in:5.15.0-1109.118USN-8163-2
linux-image-5.15.0-1109-azure-fipsUbuntu
Fixed in:5.15.0-1109.118+fips1USN-8163-1
linux-image-5.15.0-1110-azureUbuntu
Fixed in:5.15.0-1110.119~20.04.1USN-8243-1
linux-image-5.4.0-1116-bluefieldUbuntu
Fixed in:5.4.0-1116.123USN-8224-1
linux-image-5.4.0-1139-raspiUbuntu
Fixed in:5.4.0-1139.152~18.04.1USN-8098-10
Fixed in:5.4.0-1139.152USN-8098-10
linux-image-5.4.0-1161-azureUbuntu
Fixed in:5.4.0-1161.167~18.04.1USN-8201-1
linux-image-6.17.0-1017-oemUbuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-6.8.0-1029-xilinxUbuntu
Fixed in:6.8.0-1029.30USN-8261-1
linux-image-6.8.0-1052-azure-fipsUbuntu
Fixed in:6.8.0-1052.58+fips1USN-8165-1
linux-image-aws-4.15Ubuntu
Fixed in:4.15.0.1191.189USN-8266-1
linux-image-aws-fipsUbuntu
Fixed in:4.15.0.2129.123USN-8266-1
linux-image-aws-fips-4.15Ubuntu
Fixed in:4.15.0.2129.123USN-8266-1
linux-image-aws-hweUbuntu
Fixed in:4.15.0.1191.204~16.04.1USN-8266-1
linux-image-aws-lts-18.04Ubuntu
Fixed in:4.15.0.1191.189USN-8266-1
linux-image-azureUbuntu
Fixed in:4.15.0.1200.215~16.04.1USN-8267-1
Fixed in:5.4.0.1161.167~18.04.1USN-8201-1
Fixed in:5.15.0.1110.119~20.04.1USN-8243-1
linux-image-azure-4.15Ubuntu
Fixed in:4.15.0.1200.168USN-8266-1
linux-image-azure-5.15Ubuntu
Fixed in:5.15.0.1110.119~20.04.1USN-8243-1
Fixed in:5.15.0.1109.107USN-8163-2
linux-image-azure-5.4Ubuntu
Fixed in:5.4.0.1161.167~18.04.1USN-8201-1
linux-image-azure-cvmUbuntu
Fixed in:5.15.0.1110.119~20.04.1USN-8243-1
linux-image-azure-fipsUbuntu
Fixed in:4.15.0.2109.105USN-8267-1
Fixed in:5.15.0.1109.94USN-8163-1
Fixed in:6.8.0-1052.58+fips1USN-8165-1
linux-image-azure-fips-4.15Ubuntu
Fixed in:4.15.0.2109.105USN-8267-1
linux-image-azure-fips-5.15Ubuntu
Fixed in:5.15.0.1109.94USN-8163-1
linux-image-azure-fips-6.8Ubuntu
Fixed in:6.8.0-1052.58+fips1USN-8165-1
linux-image-azure-lts-18.04Ubuntu
Fixed in:4.15.0.1200.168USN-8266-1
linux-image-azure-lts-22.04Ubuntu
Fixed in:5.15.0.1109.107USN-8163-2
linux-image-bluefieldUbuntu
Fixed in:5.4.0.1116.112USN-8224-1
linux-image-bluefield-5.4Ubuntu
Fixed in:5.4.0.1116.112USN-8224-1
linux-image-fipsUbuntu
Fixed in:4.15.0.1146.143USN-8266-1
linux-image-gcpUbuntu
Fixed in:4.15.0.1184.201~16.04.1USN-8266-1
linux-image-gcp-4.15Ubuntu
Fixed in:4.15.0.1184.197USN-8266-1
linux-image-gcp-fipsUbuntu
Fixed in:4.15.0.2092.90USN-8266-1
linux-image-gcp-fips-4.15Ubuntu
Fixed in:4.15.0.2092.90USN-8266-1
linux-image-gcp-lts-18.04Ubuntu
Fixed in:4.15.0.1184.197USN-8266-1
linux-image-genericUbuntu
Fixed in:4.15.0.249.233USN-8266-1
linux-image-generic-hwe-16.04Ubuntu
Fixed in:4.15.0.249.261~16.04.1USN-8266-1
linux-image-gkeUbuntu
Fixed in:4.15.0.1184.201~16.04.1USN-8266-1
linux-image-intel-iot-realtimeUbuntu
Fixed in:5.15.0.1096.100USN-8164-1
linux-image-intel-iot-realtime-5.15Ubuntu
Fixed in:5.15.0.1096.100USN-8164-1
linux-image-kvmUbuntu
Fixed in:4.15.0.1173.164USN-8266-1
linux-image-lowlatencyUbuntu
Fixed in:4.15.0.249.233USN-8266-1
linux-image-lowlatency-hwe-16.04Ubuntu
Fixed in:4.15.0.249.261~16.04.1USN-8266-1
linux-image-oemUbuntu
Fixed in:4.15.0.249.261~16.04.1USN-8266-1
linux-image-oem-24.04Ubuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-oem-24.04aUbuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-oem-24.04bUbuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-oem-24.04cUbuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-oem-24.04dUbuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-oem-6.17Ubuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-image-oracleUbuntu
Fixed in:4.15.0.1153.164~16.04.1USN-8267-1
linux-image-oracle-4.15Ubuntu
Fixed in:4.15.0.1153.158USN-8266-1
linux-image-oracle-lts-18.04Ubuntu
Fixed in:4.15.0.1153.158USN-8266-1
linux-image-raspiUbuntu
Fixed in:5.4.0.1139.170USN-8098-10
linux-image-raspi-5.4Ubuntu
Fixed in:5.4.0.1139.152~18.04.1USN-8098-10
Fixed in:5.4.0.1139.170USN-8098-10
linux-image-raspi-hwe-18.04Ubuntu
Fixed in:5.4.0.1139.152~18.04.1USN-8098-10
linux-image-raspi2Ubuntu
Fixed in:5.4.0.1139.170USN-8098-10
linux-image-virtualUbuntu
Fixed in:4.15.0.249.233USN-8266-1
linux-image-virtual-hwe-16.04Ubuntu
Fixed in:4.15.0.249.261~16.04.1USN-8266-1
linux-image-xilinxUbuntu
Fixed in:6.8.0.1029.30USN-8261-1
linux-image-xilinx-6.8Ubuntu
Fixed in:6.8.0.1029.30USN-8261-1
linux-image-xilinx-zynqmpUbuntu
Fixed in:6.8.0.1029.30USN-8261-1
linux-intel-iot-realtimeUbuntu
Fixed in:5.15.0-1096.98USN-8164-1
linux-kvmUbuntu
Fixed in:4.15.0-1173.178USN-8266-1
linux-oem-6.17Ubuntu
Fixed in:6.17.0-1017.17USN-8152-1
linux-oracleUbuntu
Fixed in:4.15.0-1153.164~16.04.1USN-8267-1
Fixed in:4.15.0-1153.164USN-8266-1
linux-raspiUbuntu
Fixed in:5.4.0-1139.152USN-8098-10
linux-raspi-5.4Ubuntu
Fixed in:5.4.0-1139.152~18.04.1USN-8098-10
linux-xilinxUbuntu
Fixed in:6.8.0-1029.30USN-8261-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityNone
IntegrityNone
AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U

Exploit Intelligence

0.18%probability of exploitation in 30 days
7thpercentile

Low risk: more likely to be exploited than 7% of all known CVEs.

References

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Markdown

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-24.