CVE-2023-6915

System crash via unchecked NULL bitmap

Published Jan 15, 2024 · Updated Nov 6, 2025

NULL pointer dereference in Red Hat Enterprise Linux 8 and 9 kernels allows local users to crash the system by freeing an unallocated ID. In ida_free in lib/idr.c, xas_load returns NULL when no nearby IDs are allocated, but the else branch dereferences bitmap->bitmap without first checking bitmap. A local execution path must invoke ida_free for an ID it does not own; the reported consequence is a kernel crash and service interruption.

CVSS severity6.2
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Red Hat Enterprise Linux 8 and 9 kernels allows local users to crash the system by freeing an unallocated ID. In ida_free in lib/idr.c, xas_load returns NULL when no nearby IDs are allocated, but the else branch dereferences bitmap->bitmap without first checking bitmap. A local execution path must invoke ida_free for an ID it does not own; the reported consequence is a kernel crash and service interruption.

The record

CVE
CVE-2023-6915
Published
Jan 15, 2024
Updated
Nov 6, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 8
Classifications
CWE-476, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Red Hat · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

6.2Red HatCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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