{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "f628d799972799023d32c2542bb2639eb8c4f84e"
            },
            {
              "fixed": "94ae5145c520618802b0a24c047dcd5f05835db8"
            },
            {
              "fixed": "058ffa81f9440c5b4714685611cf697fd3739ec9"
            },
            {
              "fixed": "2571b35883268a266554e80d368e67fdfea7fb9d"
            },
            {
              "fixed": "201db408872ca12cf09e36bf0f560138c3dcfa1c"
            },
            {
              "fixed": "9ec08b7499a62c6d4afa93d36ab47a43fcad57d1"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.6.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89657.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: validate OSD extent maps before cursor advance\n\nnet/ceph/osd_client.c:osd_sparse_read() validates that the sparse-read\ndata length matches the summed extent lengths, but it does not validate\nthat each OSD-supplied extent is monotonic and lies inside the original\nrequest range. A malformed authenticated OSD reply can advertise a\nfar-forward nonzero extent offset with a matching data length and make\nthe client advance the message-data cursor beyond the request buffer.\nThis reaches the BUG_ON(!*length) assertion in ceph_msg_data_next() from\nthe client receive path.\n\nImpact: A malicious or compromised authenticated Ceph OSD peer can crash\na kernel Ceph client via a malformed sparse-read reply.\n\nReject sparse extent maps that overflow, move backwards, overlap, or\nextend outside the original sparse-read request before advancing the\ncursor.\n\n[ idryomov: perform sparse_extent_map_valid() check a bit earlier,\n  in CEPH_SPARSE_READ_DATA_LEN instead of CEPH_SPARSE_READ_DATA_PRE\n  state ]",
  "id": "CVE-2026-89657",
  "modified": "2026-09-15T03:30:40.375838685Z",
  "published": "2026-09-11T19:45:46.118Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/058ffa81f9440c5b4714685611cf697fd3739ec9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/201db408872ca12cf09e36bf0f560138c3dcfa1c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2571b35883268a266554e80d368e67fdfea7fb9d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/94ae5145c520618802b0a24c047dcd5f05835db8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9ec08b7499a62c6d4afa93d36ab47a43fcad57d1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89657.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89657"
    },
    {
      "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: validate OSD extent maps before cursor advance"
}