CVE-2026-98368
Description
A flaw was found in the Linux kernel's IPsec Encapsulating Security Payload (ESP) subsystem. When transmitting network packets using zero-copy operations on out-of-place paths, the kernel modifies packet fragment structures without properly updating reference counts for managed memory pages. A local user can exploit this vulnerability by sending network traffic with zero-copy buffers, causing pages to be prematurely released while still in use. This flaw leads to a use-after-free condition that can result in a Denial of Service (DoS) through a kernel crash or potentially allow privilege escalation.
Statement
This vulnerability is rated as Moderate impact because successful exploitation requires local user access and is constrained to systems routing zero-copy socket traffic across IPsec ESP tunnels utilizing out-of-place cryptographic processing. Although the underlying use-after-free flaw could lead to a kernel crash or potential local privilege escalation, it cannot be triggered remotely by network adversaries. Consequently, typical deployments lacking IPsec encapsulation or unprivileged zero-copy networking remain unexposed to remote threats, keeping the risk contained.
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 | 7 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | 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:H/PR:L/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
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an adversary can prevent a reference count from reaching zero, then resources might not be released when they are supposed to, thus causing resources to become scarce for future needs.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If an adversary can cause a reference count to reach zero when the resource is still in use, then a resource might be released before it is supposed to be, possibly forcing an error that causes the product to crash or exit out of its current operation.
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