Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 BPF kernel/bpf/btf.c btf_var_show resolved_ids null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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8.7$0-$5k0.19

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1. Affected by this issue is the function btf_var_show of the file kernel/bpf/btf.c of the component BPF. The manipulation of the argument resolved_ids leads to null pointer dereference. This vulnerability is traded as CVE-2026-98063. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 and classified as very critical. This issue affects the function btf_var_show of the file kernel/bpf/btf.c of the component BPF. The manipulation of the argument resolved_ids with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix NULL-ptr-deref in btf_var_show() btf_var_show() calls btf_type_id_resolve() unconditionally, which dereferences btf->resolved_ids. That is NULL for a base BTF - e.g. the vmlinux BTF that bpf_snprintf_btf() renders against - since base BTF is not resolved during parsing. btf_modifier_show() guards this with 'if (btf->resolved_ids)', but btf_var_show() does not. A BPF program that passes the type_id of a BTF_KIND_VAR from the vmlinux BTF to bpf_snprintf_btf() thus NULL-derefs: KASAN: probably user-memory-access in range [0x46638-0x4663f] RIP: 0010:btf_var_show (kernel/bpf/btf.c:2929) Call Trace: <TASK> btf_type_show (kernel/bpf/btf.c:8259) btf_type_snprintf_show (kernel/bpf/btf.c:8329) bpf_snprintf_btf (kernel/trace/bpf_trace.c:1047) bpf_prog_test_run_raw_tp (net/bpf/test_run.c:829) __sys_bpf (kernel/bpf/syscall.c:4804) do_syscall_64 (arch/x86/entry/syscall_64.c:84) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) </TASK> Resolve the var's type directly with btf_type_skip_modifiers() when resolved_ids is NULL, mirroring btf_modifier_show().

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-98063 since 09/25/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch e472ae0d97865e2021ee668a13eab64013aebf23/ca086264e98108b44fdf53971033811a48defe2b/ea383b3ea56979ce54c8aa88e6ec67164986c401/5403a383f52fc0905703b488f7c3db4b2447dc58 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.111/6.18.53/7.2.7/7.3-rc2
Patch: e472ae0d97865e2021ee668a13eab64013aebf23/ca086264e98108b44fdf53971033811a48defe2b/ea383b3ea56979ce54c8aa88e6ec67164986c401/5403a383f52fc0905703b488f7c3db4b2447dc58

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98063 (🔒)
GCVE (CVE): GCVE-0-2026-98063
GCVE (VulDB): GCVE-100-410279

Entryinfo

Created: 09/25/2026 16:22
Changes: 09/25/2026 16:22 (61)
Complete: 🔍
Cache ID: 216::103

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