{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23406 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23406 is a high-severity memory corruption vulnerability in Linux kernel, published on 1 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-23406 and fix it if it is affected.\n\nWhat it is: CVE-2026-23406 is a high-severity memory corruption vulnerability in Linux kernel, published on 1 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-23406 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-23406/ (Markdown: https://insights.sbomify.com/CVE-2026-23406/index.md)","id":"CVE-2026-23406","markdown":"https://insights.sbomify.com/CVE-2026-23406/index.md","name":"CVE-2026-23406","record":{"aliases":["AZL-82022","BELL-CVE-2026-23406","DEBIAN-CVE-2026-23406","GHSA-56hx-r887-5w6h","UBUNTU-CVE-2026-23406"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A side-effect bug in the AppArmor match_char macro causes out-of-bounds reads during file access, potentially leading to crashes or information leaks.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix side-effect bug in match_char() macro usage\n\nThe match_char() macro evaluates its character parameter multiple\ntimes when traversing differential encoding chains. When invoked\nwith *str++, the string pointer advances on each iteration of the\ninner do-while loop, causing the DFA to check different characters\nat each iteration and therefore skip input characters.\nThis results in out-of-bounds reads when the pointer advances past\nthe input buffer boundary.\n\n[   94.984676] ==================================================================\n[   94.985301] BUG: KASAN: slab-out-of-bounds in aa_dfa_match+0x5ae/0x760\n[   94.985655] Read of size 1 at addr ffff888100342000 by task file/976\n\n[   94.986319] CPU: 7 UID: 1000 PID: 976 Comm: file Not tainted 6.19.0-rc7-next-20260127 #1 PREEMPT(lazy)\n[   94.986322] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n[   94.986329] Call Trace:\n[   94.986341]  \u003cTASK\u003e\n[   94.986347]  dump_stack_lvl+0x5e/0x80\n[   94.986374]  print_report+0xc8/0x270\n[   94.986384]  ? aa_dfa_match+0x5ae/0x760\n[   94.986388]  kasan_report+0x118/0x150\n[   94.986401]  ? aa_dfa_match+0x5ae/0x760\n[   94.986405]  aa_dfa_match+0x5ae/0x760\n[   94.986408]  __aa_path_perm+0x131/0x400\n[   94.986418]  aa_path_perm+0x219/0x2f0\n[   94.986424]  apparmor_file_open+0x345/0x570\n[   94.986431]  security_file_open+0x5c/0x140\n[   94.986442]  do_dentry_open+0x2f6/0x1120\n[   94.986450]  vfs_open+0x38/0x2b0\n[   94.986453]  ? may_open+0x1e2/0x2b0\n[   94.986466]  path_openat+0x231b/0x2b30\n[   94.986469]  ? __x64_sys_openat+0xf8/0x130\n[   94.986477]  do_file_open+0x19d/0x360\n[   94.986487]  do_sys_openat2+0x98/0x100\n[   94.986491]  __x64_sys_openat+0xf8/0x130\n[   94.986499]  do_syscall_64+0x8e/0x660\n[   94.986515]  ? count_memcg_events+0x15f/0x3c0\n[   94.986526]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986540]  ? handle_mm_fault+0x1639/0x1ef0\n[   94.986551]  ? vma_start_read+0xf0/0x320\n[   94.986558]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986561]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986563]  ? fpregs_assert_state_consistent+0x50/0xe0\n[   94.986572]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986574]  ? arch_exit_to_user_mode_prepare+0x9/0xb0\n[   94.986587]  ? srso_alias_return_thunk+0x5/0xfbef5\n[   94.986588]  ? irqentry_exit+0x3c/0x590\n[   94.986595]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n[   94.986597] RIP: 0033:0x7fda4a79c3ea\n\nFix by extracting the character value before invoking match_char,\nensuring single evaluation per outer loop.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"apparmor: fix side-effect bug in match_char() macro usage","id":"CVE-2026-23406","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"apparmor: fix missing bounds check on DEFAULT table in verify_dfa()","id":"CVE-2026-23407"},"packages":[],"prev":{"headline":"apparmor: fix: limit the number of levels of policy namespaces","id":"CVE-2026-23405"},"products":["Linux"],"published":"2026-04-01","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A side-effect bug in the AppArmor match_char macro causes out-of-bounds reads during file access, potentially leading to crashes or information leaks.","url":"https://insights.sbomify.com/CVE-2026-23406/"}