CVE-2026-68159
Description
A flaw was found in libceph in the Linux kernel. A remote attacker, acting as a malicious monitor, could send a specially crafted OSDMap (Object Storage Device Map) with an overly long pg_temp or pg_upmap entry. This could lead to a stack out-of-bounds write, resulting in a kernel bug and potentially a denial of service.
Mitigation
If the system does not require the `libceph` module for Ceph cluster connectivity, prevent the `ceph` kernel module from loading by blacklisting it. Create a file `/etc/modprobe.d/ceph.conf` with the content `blacklist ceph`. After creating the file, regenerate the initramfs using `dracut -f -v` and reboot the system for the changes to take effect. If `libceph` is in use, restrict network access to Ceph monitors to trusted hosts through firewall rules to reduce the attack surface.
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 | 8.8 | N/A | 9.8 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| 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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Frequently Asked Questions
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