{"id":"CVE-2026-68433","state":"PUBLISHED","title":"libceph: bound get_version reply decode to front len","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound get_version reply decode to front len\n\nhandle_get_version_reply() uses msg->front_alloc_len as the decode\nboundary for MON_GET_VERSION_REPLY.  That is the size of the reused\nreply buffer, not the number of bytes actually received.\n\nA truncated reply can therefore pass ceph_decode_need() and decode the\nsecond u64 from stale tail bytes left in the buffer by an earlier\nmessage, causing an uninitialized memory read.\n\nUse msg->front.iov_len as the receive-side decode boundary, matching\nother libceph reply handlers and limiting decoding to the bytes that\nwere actually read from the wire.","publishedAt":"2026-08-12T00:07:20.455Z","updatedAt":"2026-10-19T21:09:10.325Z","severity":{"score":8.6,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"1307028f082756bf453e1889aee9983d30643a4b","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"72a35070fcefa229b1b031aa7482ad3788e18f07","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"340e0386aa39da181015bee38f309018c335ce16","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"d60de8253c85a02d0e6194b0735e7a562981a04c","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"4e7ebfaa0d14cf50e44041bfde38070d6dbc019f","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"0d934c934ec746d53fc7e4f53239792647bbae63","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/mon_client.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.16","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/mon_client.c"]}],"references":["https://git.kernel.org/stable/c/1307028f082756bf453e1889aee9983d30643a4b","https://git.kernel.org/stable/c/f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e","https://git.kernel.org/stable/c/72a35070fcefa229b1b031aa7482ad3788e18f07","https://git.kernel.org/stable/c/340e0386aa39da181015bee38f309018c335ce16","https://git.kernel.org/stable/c/d60de8253c85a02d0e6194b0735e7a562981a04c","https://git.kernel.org/stable/c/4e7ebfaa0d14cf50e44041bfde38070d6dbc019f","https://git.kernel.org/stable/c/0d934c934ec746d53fc7e4f53239792647bbae63","https://git.kernel.org/stable/c/d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68433.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68433","state":"PUBLISHED","datePublished":"2026-08-12T00:07:20.455Z","dateUpdated":"2026-10-19T21:09:10.325Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.393Z"},"containers":{"cna":{"title":"libceph: bound get_version reply decode to front len","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: bound get_version reply decode to front len\n\nhandle_get_version_reply() uses msg->front_alloc_len as the decode\nboundary for MON_GET_VERSION_REPLY.  That is the size of the reused\nreply buffer, not the number of bytes actually received.\n\nA truncated reply can therefore pass ceph_decode_need() and decode the\nsecond u64 from stale tail bytes left in the buffer by an earlier\nmessage, causing an uninitialized memory read.\n\nUse msg->front.iov_len as the receive-side decode boundary, matching\nother libceph reply handlers and limiting decoding to the bytes that\nwere actually read from the wire."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"1307028f082756bf453e1889aee9983d30643a4b","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"72a35070fcefa229b1b031aa7482ad3788e18f07","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"340e0386aa39da181015bee38f309018c335ce16","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"d60de8253c85a02d0e6194b0735e7a562981a04c","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"4e7ebfaa0d14cf50e44041bfde38070d6dbc019f","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"0d934c934ec746d53fc7e4f53239792647bbae63","versionType":"git"},{"version":"513a8243d67f8e8d27f2883bd2f18bc87c7ca376","status":"affected","lessThan":"d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/mon_client.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.16","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ceph/mon_client.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/1307028f082756bf453e1889aee9983d30643a4b"},{"url":"https://git.kernel.org/stable/c/f6cbf6878f3a1503c872ba8f1e69a58ee68d8b2e"},{"url":"https://git.kernel.org/stable/c/72a35070fcefa229b1b031aa7482ad3788e18f07"},{"url":"https://git.kernel.org/stable/c/340e0386aa39da181015bee38f309018c335ce16"},{"url":"https://git.kernel.org/stable/c/d60de8253c85a02d0e6194b0735e7a562981a04c"},{"url":"https://git.kernel.org/stable/c/4e7ebfaa0d14cf50e44041bfde38070d6dbc019f"},{"url":"https://git.kernel.org/stable/c/0d934c934ec746d53fc7e4f53239792647bbae63"},{"url":"https://git.kernel.org/stable/c/d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","baseScore":8.6,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The malformed MON_GET_VERSION_REPLY arrives over the ceph messenger TCP connection to a monitor; a malicious/compromised ceph-mon or an on-path attacker on the msgr1/crc-mode session triggers the bug purely with received network data.\nAC:L - The attacker fully controls the reply's hdr.front_len and tid, so truncating the reply to 8 bytes reliably makes the handler decode past the received data every time; no race or memory-layout condition outside attacker control is involved.\nPR:N - The vulnerable decode runs on any reply the client accepts for an outstanding generic request; the attacker acts as the remote server/peer and needs no credentials or account on the victim kernel client.\nUI:N - An already-mounted CephFS/RBD client issues mon_get_version requests automatically (osdmap checks, pool-dne checks, remount/latest-map waits), so no local user action is needed once the client is connected.\nS:U - The uninitialized read and the resulting bogus epoch stay within the kernel's own libceph client state; no security authority other than the affected kernel is impacted.\nC:L - Eight bytes of uninitialized kvmalloc'd heap (or stale bytes of a prior reply) are consumed as req->u.newest; the read stays inside the 32-byte allocation and is not copied to userspace, so it is a small bounded uninitialized-memory disclosure that only leaks indirectly through client behaviour.\nI:L - The attacker causes kernel state (req->u.newest, r_map_dne_bound, linger map_dne_bound) to be populated from uninitialized memory rather than the wire, corrupting osdmap-epoch bookkeeping and leading to wrong pool-does-not-exist decisions, but gives no arbitrary write.\nA:H - A zero stale value trips WARN_ON(greq->result || !greq->u.newest) in map_check_cb()/linger_map_check_cb() (panic with panic_on_warn), while a huge garbage epoch makes ceph_monc_wait_osdmap() block until mount_timeout or indefinitely and makes check_pool_dne() abort in-flight requests with -ENOENT; all repeatable at will."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:35:33.508Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68433","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:48:55.526707Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","type":"CWE","description":"CWE-125 Out-of-bounds Read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:09:10.325Z"}}]}}}