{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-64538 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64538 is a vulnerability in Linux, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-64538 and fix it if it is affected.\n\nWhat it is: CVE-2026-64538 is a vulnerability in Linux, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-64538 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2026-64538/ (Markdown: https://insights.sbomify.com/CVE-2026-64538/index.md)","id":"CVE-2026-64538","markdown":"https://insights.sbomify.com/CVE-2026-64538/index.md","name":"CVE-2026-64538","record":{"aliases":["AZL-94050","BELL-CVE-2026-64538","DEBIAN-CVE-2026-64538","GHSA-c37c-frr8-rx54","UBUNTU-CVE-2026-64538"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A null pointer dereference in the Linux kernel IPv6 stack allows remote attackers to cause a denial of service via crafted Router Advertisement packets.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: Fix null-ptr-deref in fib6_nh_mtu_change().\n\nfib6_nh_mtu_change() re-fetches idev via __in6_dev_get(arg-\u003edev) and\ndereferences idev-\u003ecnf.mtu6 without a NULL check. addrconf_ifdown()\nclears dev-\u003eip6_ptr with RCU_INIT_POINTER() after rt6_disable_ip() has\nreleased tb6_lock, so the RA-driven MTU walk can observe a NULL idev and\noops. The caller rt6_mtu_change_route() guards its own __in6_dev_get(),\nbut this re-fetch is unguarded; nexthop-backed routes survive\naddrconf_ifdown()'s flush, so the walk still reaches it after ip6_ptr is\nnulled.\n\nReturn 0 when idev is NULL, matching rt6_mtu_change_route() and the\nfib6_mtu() fix in commit 5ad509c1fdad (\"ipv6: Fix null-ptr-deref in\nfib6_mtu().\").\n\n  Oops: general protection fault, ... KASAN: null-ptr-deref in range\n        [0x00000000000002a8-0x00000000000002af]\n  RIP: 0010:fib6_nh_mtu_change+0x203/0x990\n   rt6_mtu_change_route+0x141/0x1d0\n   __fib6_clean_all+0xd0/0x160\n   rt6_mtu_change+0xb4/0x100\n   ndisc_router_discovery+0x24b5/0x2cb0\n   icmpv6_rcv+0x12e9/0x1710\n   ipv6_rcv+0x39b/0x410","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":"ipv6: Fix null-ptr-deref in fib6_nh_mtu_change().","id":"CVE-2026-64538","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"Bluetooth: eir: Fix stack OOB write when prepending the Flags AD","id":"CVE-2026-64539"},"packages":[],"prev":{"headline":"bridge: cfm: reject invalid CCM interval at configuration time","id":"CVE-2026-64537"},"products":["Linux"],"published":"2026-07-27","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A null pointer dereference in the Linux kernel IPv6 stack allows remote attackers to cause a denial of service via crafted Router Advertisement packets.","url":"https://insights.sbomify.com/CVE-2026-64538/"}