{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68156", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.371Z", "datePublished": "2026-08-10T11:59:22.514Z", "dateUpdated": "2026-08-19T16:30:25.089Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:30:25.089Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: refresh auth->authorizer_buf{,_len} after authorizer update\n\nceph_x_create_authorizer() caches au->buf->vec.iov_base and\nau->buf->vec.iov_len in struct ceph_auth_handshake. These\ncached values are then used by the messenger connect code when\nsending the authorizer.\n\nceph_x_update_authorizer() can rebuild the authorizer when a newer\nservice ticket is available. If the rebuilt authorizer no longer\nfits in the existing buffer, ceph_x_build_authorizer() drops its\nreference to au->buf and allocates a new one. If this is the final\nreference, ceph_buffer_put() frees the old ceph_buffer and its\nvec.iov_base, but auth->authorizer_buf still points at that freed\nmemory.\n\nA subsequent msgr1 reconnect can therefore queue the stale pointer\nand trigger a KASAN slab-use-after-free in _copy_from_iter() while\ntcp_sendmsg() copies the authorizer.\n\nRefresh auth->authorizer_buf and auth->authorizer_buf_len after a\nsuccessful authorizer rebuild so the messenger sends the current\nbuffer." } ], "metrics": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:N - A compromised or malicious Ceph monitor/OSD delivers rotated cephx service tickets over TCP that increase secret_id and can enlarge the authorizer; on subsequent msgr1 reconnect the stale authorizer_buf is copied in tcp_sendmsg, so the UAF is reachable from the network peer without local syscall access.\nAC:L - An attacker controlling the Ceph cluster can deterministically issue a larger rotated ticket to force ceph_buffer realloc in ceph_x_update_authorizer, then trigger an msgr1 OSD/MDS/MON reconnect; no victim-specific memory layout or uncontrollable race is required.\nPR:N - Exploitation requires no privileges on the victim host; any kernel Ceph/RBD/CephFS client already connected to an attacker-controlled or compromised cluster is sufficient, matching other libceph client CVEs where the remote peer drives the bug.\nUI:N - After initial Ceph client setup, service-ticket rotation and messenger reconnects occur automatically; no further interactive user action is needed to reach the stale-buffer send path.\nS:U - The slab UAF corrupts kernel heap memory on the Ceph client host for local privilege escalation or crash, but does not cross VM, IOMMU, or container sandbox boundaries to another security authority.\nC:H - KASAN-confirmed slab use-after-free in _copy_from_iter during authorizer transmission reads freed kmalloc memory, which can disclose adjacent kernel pointers and is classed as exploitable arbitrary read per kernel UAF guidance.\nI:H - Freed authorizer buffers can be reclaimed with attacker-controlled data before reconnect, enabling heap corruption and control-flow hijack during the stale-pointer copy, consistent with kernel UAF write primitive scoring.\nA:H - The reported KASAN slab-use-after-free in tcp_sendmsg while copying the authorizer reliably causes kernel oops or panic on Ceph client reconnect, and remains repeatable whenever tickets are rotated and msgr1 reconnects." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ceph/auth_x.c" ], "versions": [ { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "2334e9997308305ee4fd508fdfe6086c4150ed60", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "79a273df64238a4ade8b709689a78589f755b8ef", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "26f814187abceee90dbb29a02133adb4786fbb13", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "9d37aec9ffe4e743dabc3f84502e9723e17a30d4", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "75e82e8944ac1efe9fdb88bd2f14d9a031282bdf", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "0060ec912292a550198d8d18ac95b433c92a7091", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "5ecfcd5c05866f185357700b81b461dae4f5ebb2", "status": "affected", "versionType": "git" }, { "version": "0bed9b5c523d577378b6f83eab5835fe30c27208", "lessThan": "937d61f86d377a3aa578adae7a3dfcecdddf9d89", "status": "affected", "versionType": "git" }, { "version": "29c65a277a64645af853e8c9a9b3dda0ddc421e0", "status": "affected", "versionType": "git" }, { "version": "d2c7223497cf8228416c70e3f4238ddd6c5bdf3c", "status": "affected", "versionType": "git" }, { "version": "3.4.50", "lessThan": "3.5", "status": "affected", "versionType": "semver" }, { "version": "3.9.7", "lessThan": "3.10", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ceph/auth_x.c" ], "versions": [ { "version": "3.10", "status": "affected" }, { "version": "0", "lessThan": "3.10", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.10", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.9.7" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/2334e9997308305ee4fd508fdfe6086c4150ed60" }, { "url": "https://git.kernel.org/stable/c/79a273df64238a4ade8b709689a78589f755b8ef" }, { "url": "https://git.kernel.org/stable/c/26f814187abceee90dbb29a02133adb4786fbb13" }, { "url": "https://git.kernel.org/stable/c/9d37aec9ffe4e743dabc3f84502e9723e17a30d4" }, { "url": "https://git.kernel.org/stable/c/75e82e8944ac1efe9fdb88bd2f14d9a031282bdf" }, { "url": "https://git.kernel.org/stable/c/0060ec912292a550198d8d18ac95b433c92a7091" }, { "url": "https://git.kernel.org/stable/c/5ecfcd5c05866f185357700b81b461dae4f5ebb2" }, { "url": "https://git.kernel.org/stable/c/937d61f86d377a3aa578adae7a3dfcecdddf9d89" } ], "title": "libceph: refresh auth->authorizer_buf{,_len} after authorizer update", "x_generator": { "engine": "bippy-1.2.0" } } } }