CVE-2026-68155

High

In the Linux kernel, the following vulnerability has been resolved: libceph: Reject monmaps advertising zero monitors A message of type CEPH_MSG_MON_MAP contains a monmap that is sent from a monitor to the client. This monmap contains information about the existing monitors in the cluster. Currently, a monmap indicating that there are zero monitors in the cluster is treated as valid. However, it is impossible to have zero monitors in the cluster and still receive a valid monmap from a monitor. Therefore, such a monmap must be corrupted and should be treated as invalid. Furthermore, a monmap with a monitor count of zero can subsequently crash the client when attempting to open a session with a monitor in __open_session(). This happens because the "BUG_ON(monc->monmap->num_mon < 1)" assertion in pick_new_mon() is triggered. This patch extends a check in ceph_monmap_decode() to also reject arriving mon_maps with num_mon == 0 rather than only with num_mon > CEPH_MAX_MON. [ idryomov: drop "log output for unusual values of num_mon" part ]

Package Linux Kernel
Published 2026-08-10
Last modified 2026-10-03
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.5

out of 10
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 2.6.34 and later are affected. Fixed in 5.10.271, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2 and their respective stable series.

Affected from
≥ 2.6.34
Fixed in
✓ 5.10.271 5.10.x ✓ 5.15.216 5.15.x ✓ 6.1.183 6.1.x ✓ 6.6.148 6.6.x ✓ 6.12.101 6.12.x ✓ 6.18.42 6.18.x ✓ 7.1.6 7.1.x ✓ 7.2

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2026-68155?

    CVE-2026-68155 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 . It affects Linux kernel versions from 2.6.34 onward and has been patched in 5.10.271, 5.15.216, 6.1.183 and others. CVE-2026-68155 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-68155?

    CVE-2026-68155 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-68155?

    Yes. CVE-2026-68155 has been patched. Fixed versions include 5.10.271, 5.15.216, 6.1.183 and others. If you are running Linux kernel 2.6.34 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-68155 actively exploited?

    No. CVE-2026-68155 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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