CVE-2026-97610
Description
A flaw was found in the Linux kernel's netfs (network filesystem) subsystem. A local user can cause a Denial of Service (DoS) or unexpected system behavior during synchronous unbuffered write operations on network filesystems, such as CIFS (Common Internet File System). When an initial write preparation step fails or an empty data iterator is encountered, the kernel exits early without initializing a return variable. Consequently, an arbitrary value is returned instead of the actual error status, resulting in incorrect error handling and potential system instability.
Statement
A moderate impact flaw was found in the Linux kernel's netfs (network filesystem) subsystem. In netfs_unbuffered_write(), the return value variable is left uninitialized when preparation of the first subrequest fails or when an empty data iterator is encountered. As a result, a synchronous unbuffered write operation - reachable through CIFS, for example when cifs_prepare_write() fails to reopen a file or obtain credits - can return an unrelated error or an incorrect value instead of the actual write error status. A local user able to perform write operations on a mounted network filesystem could use this to cause incorrect error handling, unexpected system behavior, or a denial of service. Red Hat rated this flaw Moderate (CVSS 3.1: 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Most Red Hat Enterprise Linux streams and OpenShift Container Platform releases are not affected because the vulnerable code is not present in their kernels. The kernel in Red Hat Enterprise Linux 10.3 and 10.4 and in Red Hat In-Vehicle OS 2 streams is affected, with the fix deferred in line with the moderate, local, privilege-required nature of the issue; the residual risk while the fix is deferred is incorrect error reporting and possible local denial of service during synchronous unbuffered writes on network filesystems such as CIFS.
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
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory; Read Application Data
When reusing a resource such as memory or a program variable, the original contents may not have been cleared before it is sent to an untrusted party.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability
The uninitialized resource may contain values that cause program flow to change in ways that the programmer did not intend, possibly leading to a crash.
Other
Technical Impact: Unexpected State; Varies by Context
The consequences vary depending on the type of resource and how it is used within the product.
Frequently Asked Questions
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