CVE-2026-98869
Description
A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) verifier. A local attacker could achieve privilege escalation by loading a specially crafted BPF program into the kernel. The vulnerability occurs because the verifier fails to properly track register states across execution paths during 32-bit operations, leading to missing zero-extension instructions. Consequently, an attacker can inject arbitrary values into 64-bit registers to bypass kernel safety checks and compromise system memory.
Statement
This vulnerability is rated as Important severity because an attacker capable of loading BPF programs can bypass verifier bounds checks to corrupt kernel memory and potentially elevate privileges. In standard Red Hat Enterprise Linux environments, unprivileged eBPF execution is disabled by default, substantially limiting exposure to accounts possessing CAP_BPF or CAP_SYS_ADMIN privileges. Therefore, exploitation by untrusted local users is constrained unless administrative access has already been obtained or unprivileged BPF is explicitly permitted.
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 | 6.7 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | High | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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