{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ba75bb98cfb93b62c54af25bf67ff90857264bbe"
            },
            {
              "fixed": "caf082ef8609a6ac26159ce115f55ab7d00231a3"
            },
            {
              "fixed": "e3ccd4ecab09b22f507f49cb7ed9990c7158ceab"
            },
            {
              "fixed": "0591a15815b498be628a937146e44487d599ba33"
            },
            {
              "fixed": "cd0d41bc569632eaaeccde9d2a6bc919ec00c407"
            },
            {
              "fixed": "e67e8b694872c9bc66996040f9de9242f6236ed9"
            },
            {
              "fixed": "3b249546f59c3d6d3592c10657f82bc3f1faa07c"
            },
            {
              "fixed": "40480eee361ed9676b3f844d532ac28b47251634"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.34"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.148"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.101"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.42"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68155.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Reject monmaps advertising zero monitors\n\nA message of type CEPH_MSG_MON_MAP contains a monmap that is sent from a\nmonitor to the client. This monmap contains information about the\nexisting monitors in the cluster. Currently, a monmap indicating that\nthere are zero monitors in the cluster is treated as valid. However, it\nis impossible to have zero monitors in the cluster and still receive a\nvalid monmap from a monitor. Therefore, such a monmap must be corrupted\nand should be treated as invalid. Furthermore, a monmap with a monitor\ncount of zero can subsequently crash the client when attempting to open\na session with a monitor in __open_session(). This happens because the\n\"BUG_ON(monc-\u003emonmap-\u003enum_mon \u003c 1)\" assertion in pick_new_mon() is\ntriggered.\n\nThis patch extends a check in ceph_monmap_decode() to also reject\narriving mon_maps with num_mon == 0 rather than only with\nnum_mon \u003e CEPH_MAX_MON.\n\n[ idryomov: drop \"log output for unusual values of num_mon\" part ]",
  "id": "CVE-2026-68155",
  "modified": "2026-08-21T03:30:08.521284266Z",
  "published": "2026-08-10T11:59:21.200Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0591a15815b498be628a937146e44487d599ba33"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b249546f59c3d6d3592c10657f82bc3f1faa07c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/40480eee361ed9676b3f844d532ac28b47251634"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/caf082ef8609a6ac26159ce115f55ab7d00231a3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd0d41bc569632eaaeccde9d2a6bc919ec00c407"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e3ccd4ecab09b22f507f49cb7ed9990c7158ceab"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e67e8b694872c9bc66996040f9de9242f6236ed9"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68155.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68155"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "libceph: Reject monmaps advertising zero monitors"
}