CVE-2026-23404

CVE-2026-23404 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

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.

Frequently asked questions

What is CVE-2026-23404?
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 severe is CVE-2026-23404?
CVE-2026-23404 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-23404 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23404?
CVE-2026-23404 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-23404?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-23404 have an EU (EUVD) identifier?
Yes. CVE-2026-23404 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17832.
When was CVE-2026-23404 published?
CVE-2026-23404 was published on 2026-04-01 and last updated on 2026-06-17.

References

Affected products (9)

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