{"api_version":"1","generated_at":"2026-08-22T07:56:58+00:00","cve":"CVE-2026-68159","urls":{"html":"https://cve.report/CVE-2026-68159","api":"https://cve.report/api/cve/CVE-2026-68159.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-68159","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68159"},"summary":{"title":"libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE\n\n__decode_pg_temp() decodes an user-controlled length but only rejects\nvalues large enough to overflow the allocation; it does not bound it to\nCEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and\napply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size\non-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends\nan OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack\nout-of-bounds write.\n\nAn OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer\nentries at decode time. The bound is well below the old overflow threshold, so\nit also covers the allocation-size overflow the previous check guarded against.\n\n  BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds\n  Write of size 4 ... by task exploit\n   kasan_report (mm/kasan/report.c:595)\n   ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833)\n   calc_target (net/ceph/osd_client.c:1638)\n   __submit_request (net/ceph/osd_client.c:2394)\n   ceph_osdc_start_request (net/ceph/osd_client.c:2490)\n   ceph_osdc_call (net/ceph/osd_client.c:5164)\n   rbd_dev_image_probe (drivers/block/rbd.c:6899)\n   do_rbd_add (drivers/block/rbd.c:7138)\n   ...\n  kernel BUG at net/ceph/osdmap.c:2670!\n\n[ idryomov: do the same in __decode_pg_upmap_items() ]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-10 13:20:02","updated_at":"2026-08-17 05:18:16"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/e36663145abd7024f0281dfb22fdef65f185845b","name":"https://git.kernel.org/stable/c/e36663145abd7024f0281dfb22fdef65f185845b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9f00f9cf2be293efe899db67dc5272e3a9c62717","name":"https://git.kernel.org/stable/c/9f00f9cf2be293efe899db67dc5272e3a9c62717","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68159","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68159","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a303bb0e58345fe9f7ab2f82b90266f2b5036058 e36663145abd7024f0281dfb22fdef65f185845b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a303bb0e58345fe9f7ab2f82b90266f2b5036058 9f00f9cf2be293efe899db67dc5272e3a9c62717 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.13","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.13 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.6 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"68159","cve":"CVE-2026-68159","epss":"0.005530000","percentile":"0.435860000","score_date":"2026-08-17","updated_at":"2026-08-18 00:11:47"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ceph/osdmap.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"e36663145abd7024f0281dfb22fdef65f185845b","status":"affected","version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","versionType":"git"},{"lessThan":"9f00f9cf2be293efe899db67dc5272e3a9c62717","status":"affected","version":"a303bb0e58345fe9f7ab2f82b90266f2b5036058","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ceph/osdmap.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.13"},{"lessThan":"4.13","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.6","versionStartIncluding":"4.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"4.13","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE\n\n__decode_pg_temp() decodes an user-controlled length but only rejects\nvalues large enough to overflow the allocation; it does not bound it to\nCEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and\napply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size\non-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends\nan OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack\nout-of-bounds write.\n\nAn OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer\nentries at decode time. The bound is well below the old overflow threshold, so\nit also covers the allocation-size overflow the previous check guarded against.\n\n  BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds\n  Write of size 4 ... by task exploit\n   kasan_report (mm/kasan/report.c:595)\n   ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833)\n   calc_target (net/ceph/osd_client.c:1638)\n   __submit_request (net/ceph/osd_client.c:2394)\n   ceph_osdc_start_request (net/ceph/osd_client.c:2490)\n   ceph_osdc_call (net/ceph/osd_client.c:5164)\n   rbd_dev_image_probe (drivers/block/rbd.c:6899)\n   do_rbd_add (drivers/block/rbd.c:7138)\n   ...\n  kernel BUG at net/ceph/osdmap.c:2670!\n\n[ idryomov: do the same in __decode_pg_upmap_items() ]"}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - Malicious pg_temp/pg_upmap data arrives in CEPH_MSG_OSD_MAP from a Ceph monitor or OSD over TCP, is decoded in libceph, and later triggers stack corruption in ceph_pg_to_up_acting_osds during RBD/CephFS/libceph client I/O.\nAC:L - A compromised or attacker-controlled monitor can publish osdmap entries with length >32 for chosen PGs; once the client subscribes, kernel I/O paths such as RBD mount/probe via calc_target deterministically invoke apply_upmap/get_temp_osds and overflow the stack buffer.\nPR:N - Exploitation requires no privileges on the victim host; any machine acting as a Ceph client that receives a forged osdmap from a cluster peer over the network can be attacked without local user capabilities or namespace tricks.\nUI:N - No victim user action is needed during exploitation beyond the host already being a Ceph client; forged osdmaps are applied automatically and the overflow fires on subsequent kernel client operations without interactive steps.\nS:U - Impact is confined to kernel memory on the Ceph client host (privilege escalation or crash); it does not cross VM, IOMMU, or sandbox boundaries to other security authorities.\nC:H - KASAN-confirmed stack out-of-bounds write in ceph_pg_to_up_acting_osds corrupts adjacent stack memory and can be leveraged for arbitrary kernel memory disclosure, not merely a bounded leak.\nI:H - Unbounded copy loops in apply_upmap() and get_temp_osds() write attacker-controlled u32 OSD IDs past the fixed osds[CEPH_PG_MAX_SIZE] stack array, enabling control-flow hijack and arbitrary kernel writes.\nA:H - The reported reproducer triggers KASAN stack-out-of-bounds followed by kernel BUG in ceph_pg_to_up_acting_osds, demonstrating a reliable kernel oops or panic from malformed osdmap processing on Ceph clients."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T04:59:55.290Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/e36663145abd7024f0281dfb22fdef65f185845b"},{"url":"https://git.kernel.org/stable/c/9f00f9cf2be293efe899db67dc5272e3a9c62717"}],"title":"libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-68159","datePublished":"2026-08-10T11:59:25.697Z","dateReserved":"2026-07-30T09:28:09.371Z","dateUpdated":"2026-08-17T04:59:55.290Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-10 13:20:02","lastModifiedDate":"2026-08-17 05:18:16","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"68159","Ordinal":"1","Title":"libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX","CVE":"CVE-2026-68159","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"68159","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX_SIZE\n\n__decode_pg_temp() decodes an user-controlled length but only rejects\nvalues large enough to overflow the allocation; it does not bound it to\nCEPH_PG_MAX_SIZE. The helper backs both pg_temp and pg_upmap decoding, and\napply_upmap()/get_temp_osds() later copy the decoded list into the fixed-size\non-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE]. A monitor that sends\nan OSDMap with a pg_temp/pg_upmap entry longer than 32 thus causes a stack\nout-of-bounds write.\n\nAn OSD set for a single PG can never exceed CEPH_PG_MAX_SIZE, so reject longer\nentries at decode time. The bound is well below the old overflow threshold, so\nit also covers the allocation-size overflow the previous check guarded against.\n\n  BUG: KASAN: stack-out-of-bounds in ceph_pg_to_up_acting_osds\n  Write of size 4 ... by task exploit\n   kasan_report (mm/kasan/report.c:595)\n   ceph_pg_to_up_acting_osds (net/ceph/osdmap.c:2617 net/ceph/osdmap.c:2833)\n   calc_target (net/ceph/osd_client.c:1638)\n   __submit_request (net/ceph/osd_client.c:2394)\n   ceph_osdc_start_request (net/ceph/osd_client.c:2490)\n   ceph_osdc_call (net/ceph/osd_client.c:5164)\n   rbd_dev_image_probe (drivers/block/rbd.c:6899)\n   do_rbd_add (drivers/block/rbd.c:7138)\n   ...\n  kernel BUG at net/ceph/osdmap.c:2670!\n\n[ idryomov: do the same in __decode_pg_upmap_items() ]","Type":"Description","Title":"libceph: bound pg_{temp,upmap,upmap_items} length to CEPH_PG_MAX"}]}}}