CVE-2026-98063
Description
A flaw was found in the Linux kernel's BPF (Berkeley Packet Filter) subsystem. When formatting data using BPF Type Format (BTF), the kernel attempts to access type identifiers without checking if they are initialized. A local user with permissions to execute BPF programs can exploit this vulnerability to trigger a NULL pointer dereference, causing a system crash and resulting in a denial of service.
Statement
A moderate severity flaw was found in the Linux kernel's BPF (Berkeley Packet Filter) subsystem. When formatting data using BPF Type Format (BTF), the btf_var_show() function calls btf_type_id_resolve() unconditionally and dereferences btf->resolved_ids, which is NULL for a base BTF such as the vmlinux BTF that bpf_snprintf_btf() renders against. A local user with permission to execute BPF programs can pass the type_id of a BTF_KIND_VAR from the vmlinux BTF to bpf_snprintf_btf(), triggering a NULL pointer dereference that crashes the kernel and results in a denial of service. Confidentiality and integrity are not impacted. Red Hat Product Security rated this flaw as Moderate (CVSS 3.1 score 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). The vulnerable code is present in the kernels shipped in Red Hat Enterprise Linux 8, 9, and 10, Red Hat In-Vehicle OS, and Red Hat OpenShift 4 streams, which are recorded as affected. Red Hat Enterprise Linux 6, 7, and 8.4 are not affected because the vulnerable code is not present in those kernels. Fixes for the affected streams are currently deferred; the residual risk is limited to local denial of service by a user who already holds the privileges needed to execute BPF programs.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
