{"id":"CVE-2026-98063","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL-ptr-deref in btf_var_show()\n\nbtf_var_show() calls btf_type_id_resolve() unconditionally, which\ndereferences btf->resolved_ids","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL-ptr-deref in btf_var_show()\n\nbtf_var_show() calls btf_type_id_resolve() unconditionally, which\ndereferences btf->resolved_ids. That is NULL for a base BTF…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"Linux","product":"Linux","affected":["Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 5756450c9a702da0efb4a993d0a6766b965736f3","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < e83fcbe3b5d4a1ffb0569bb7c280358065c6017a","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < aec0a9c1579eb9edf534960be592d09481bd7ac3","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < e472ae0d97865e2021ee668a13eab64013aebf23","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < ca086264e98108b44fdf53971033811a48defe2b","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < ea383b3ea56979ce54c8aa88e6ec67164986c401","Linux >= c4d0bfb45068d853a478b9067a95969b1886a30f < 5403a383f52fc0905703b488f7c3db4b2447dc58","Linux 5.10"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:26.840","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98063","references":[{"url":"https://git.kernel.org/stable/c/5403a383f52fc0905703b488f7c3db4b2447dc58","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5756450c9a702da0efb4a993d0a6766b965736f3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aec0a9c1579eb9edf534960be592d09481bd7ac3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ca086264e98108b44fdf53971033811a48defe2b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e0d6a06171633d3ee3f7a39b57e5c845fb2b79f2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e472ae0d97865e2021ee668a13eab64013aebf23","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e83fcbe3b5d4a1ffb0569bb7c280358065c6017a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ea383b3ea56979ce54c8aa88e6ec67164986c401","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98063.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98063"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541227"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98063"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98063"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98063.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00177,"epssPercentile":0.07178,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.843Z","slug":"CVE-2026-98063","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix NULL-ptr-deref in btf_var_show()\n\nbtf_var_show() calls btf_type_id_resolve() unconditionally, which\ndereferences btf->resolved_ids. That is NULL for a base BTF - e.g. the\nvmlinux BTF that bpf_snprintf_btf() renders against - since base BTF is\nnot resolved during parsing. btf_modifier_show() guards this with\n'if (btf->resolved_ids)', but btf_var_show() does not.\n\nA BPF program that passes the type_id of a BTF_KIND_VAR from the vmlinux\nBTF to bpf_snprintf_btf() thus NULL-derefs:\n\nKASAN: probably user-memory-access in range [0x46638-0x4663f]\nRIP: 0010:btf_var_show (kernel/bpf/btf.c:2929)\nCall Trace:\n <TASK>\n btf_type_show (kernel/bpf/btf.c:8259)\n btf_type_snprintf_show (kernel/bpf/btf.c:8329)\n bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047)\n bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829)\n __sys_bpf (kernel/bpf/syscall.c:4804)\n do_syscall_64 (arch/x86/entry/syscall_64.c:84)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n </TASK>\n\nResolve the var's type directly with btf_type_skip_modifiers() when\nresolved_ids is NULL, mirroring btf_modifier_show().\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98063.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":212378,"id":"CVE-2026-98063","ts":1790668160406,"field":"cvss","old":null,"new":"5.5"},{"seq":212377,"id":"CVE-2026-98063","ts":1790668160406,"field":"severity","old":"none","new":"medium"}]}