CVE-2026-98709
Description
A flaw was found in the Linux kernel's mac80211 wireless networking subsystem. During channel context switching operations across multiple virtual interfaces, improper tracking of link reservations can cause an active channel context to be released prematurely while still in use by the driver. A local attacker could exploit this flaw to trigger a use-after-free condition, resulting in a Denial of Service (DoS) through a system crash or potential memory corruption.
Statement
A channel context replacement can be considered complete too early because ieee80211_vif_use_reserved_switch counts reservations that belong to a different replacement operation. Another link can then finalize first and free a WILL_BE_REPLACED channel context while an unmatched link and the driver still reference it. Later beacon generation can dereference the freed object, resulting in a confirmed use-after-free and at least a kernel crash or denial of service. For the CVSS the PR:L value is used for the paranoid score because delegated CAP_NET_ADMIN, a restricted network service account, or a container administrator may control wireless configuration without having unrestricted host privileges. Reliable triggering requires a multi-link or multi-vif configuration, overlapping replacement state, and a specific completion order, so AC:H is appropriate. The issue is not proven to be directly reachable through untrusted WiFi traffic alone and AV:L is retained. In the worst defensible case the freed object could be reused and produce confidentiality or integrity impact or local privilege escalation, although a controlled reuse primitive is not established by the available code.
Mitigation
Mitigation for this issue is either not available or the currently available options don't 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 | 4.7 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | 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:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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