CVE-2026-99042
Description
A flaw was found in the Linux kernel's io_uring subsystem. When evaluating IPv6 network connections, security filters are supplied with zeroed address and port values if a caller provides a valid 24-byte address structure instead of the full 28-byte structure. A local attacker can exploit this flaw by submitting connection requests with shorter address lengths to bypass Berkeley Packet Filter (BPF) network security rules and connect to restricted destinations.
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 | 4.4 | N/A | 8.4 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Changed |
| Confidentiality | Low | N/A | High |
| Integrity Impact | Low | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality,Access Control,Availability
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity; Varies by Context
When security decisions such as authentication and authorization are made based on the values of these inputs, attackers can bypass the security of the product to access whatever is being protected. An attacker could change these inputs using customized clients or other attacks. This change might not be detected. The consequences will depend on the associated functionality, but they can range from granting additional privileges to untrusted users to bypassing important security checks. Ultimately, this weakness may lead to exposure or modification of sensitive data, system crash, or execution of arbitrary code.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
