Description
In the Linux kernel, the following vulnerability has been resolved:

ksmbd: rate limit unmapped SID errors

A client can include many structurally valid but unmapped SIDs in a DACL.
Logging every mapping failure lets one request generate hundreds of kernel
error messages.

Rate limit the message to prevent an authenticated client from flooding
the kernel log.
Published: 2026-09-25
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service through kernel log flooding
Action: Apply Patch
AI Analysis

Impact

Based on the description, it is inferred that the Linux kernel’s ksmbd component allows an authenticated client to send numerous structurally valid but unmapped Security Identifiers (SIDs) in a DACL. Each unmapped SID triggers a kernel error log entry. This reflects a CWE-770 weakness of excessive resource consumption. When the rate limiting for these log messages is removed, a single request can produce hundreds of error logs, potentially exhausting kernel log buffers and degrading system performance. The vulnerability does not grant arbitrary code execution or privilege escalation, but it can disrupt normal operation by flooding the kernel log and exhausting log space.

Affected Systems

This flaw exists in the Linux kernel. No specific kernel version is listed in the advisory, so any kernel that implements ksmbd and lacks the recent rate‑limiting fix is potentially affected. The vulnerability is vendor‑agnostic, affecting all distributions that ship the unpatched kernel.

Risk and Exploitability

The CVE is not listed in CISA’s KEV catalog. The EPSS score is <1%, indicating a low likelihood of exploitation in the wild. The CVSS score of 5.5 classifies the vulnerability as moderate severity. Nevertheless, because the attacker must have authenticated access, as inferred from the description, an insider or compromised user could intentionally flood logs to cause denial of service. The impact on availability could be significant on low‑resource or high‑security systems where log space is constrained. This resource exhaustion scenario remains a risk for administrators who depend on kernel log stability.

Generated by OpenCVE AI on September 30, 2026 at 15:12 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade to a kernel version that includes the patch implementing rate limiting for unmapped SID error logs.
  • If an immediate kernel upgrade is not possible, reduce the system’s kernel log buffer size or configure the system log daemon to discard or rotate error logs more aggressively to shield the system from exhaustion.
  • Implement monitoring of kernel error log frequency to detect abnormal growth patterns and alert administrators before log exhaustion occurs.

Generated by OpenCVE AI on September 30, 2026 at 15:12 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
History

Wed, 28 Oct 2026 19:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:7.3:rc1:*:*:*:*:*:*

Sat, 03 Oct 2026 11:15:00 +0000


Wed, 30 Sep 2026 07:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-400

Tue, 29 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Fri, 25 Sep 2026 12:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-400

Fri, 25 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: ksmbd: rate limit unmapped SID errors A client can include many structurally valid but unmapped SIDs in a DACL. Logging every mapping failure lets one request generate hundreds of kernel error messages. Rate limit the message to prevent an authenticated client from flooding the kernel log.
Title ksmbd: rate limit unmapped SID errors
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T09:14:05.620Z

Reserved: 2026-09-25T10:25:14.316Z

Link: CVE-2026-98113

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2026-09-25T11:17:42.450

Modified: 2026-10-28T18:52:59.003

Link: CVE-2026-98113

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-25T00:00:00Z

Links: CVE-2026-98113 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-30T15:15:16Z

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling