CVE-2026-68155

CVE CVE-2026-68155EUVD EUVD-2026-55541Published 2026-08-10T11:59:21.000Z

What the advisory describes

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 ]

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux patch: 6.18.42; 0 <6.18.42; patch: 7.2-rc5; 0 <7.1.6; patch: 7.1.6; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3b249546f59c3d6d3592c10657f82bc3f1faa07c; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0591a15815b498be628a937146e44487d599ba33; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <40480eee361ed9676b3f844d532ac28b47251634; patch: 6.12.101; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e67e8b694872c9bc66996040f9de9242f6236ed9; 0 <6.6.148; 0 <6.12.101; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cd0d41bc569632eaaeccde9d2a6bc919ec00c407; patch: 6.6.148

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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