{"cve":"CVE-2026-68160","nvd":{"published":"2026-08-10T13:20:02.300","modified":"2026-10-19T21:17:56.417","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix pre-auth out-of-bounds read on snaptrace in ceph_handle_caps()\n\nceph_handle_caps() reads snap_trace_len from the wire-format\nceph_mds_caps header and uses it unconditionally to build a fake\nend pointer (snaptrace + snaptrace_len) that is later handed to\nceph_update_snap_trace() in the CEPH_CAP_OP_IMPORT case:\n\n    snaptrace     = h + 1;\n    snaptrace_len = le32_to_cpu(h->snap_trace_len);\n    p             = snaptrace + snaptrace_len;\n    ...\n    case CEPH_CAP_OP_IMPORT:\n        if (snaptrace_len) {\n            ...\n            if (ceph_update_snap_trace(mdsc, snaptrace,\n                                       snaptrace + snaptrace_len,\n                                       false, &realm)) { ... }\n\nceph_update_snap_trace() then decodes a struct ceph_mds_snap_realm\nfrom snaptrace using ceph_decode_need(&p, e, sizeof(*ri), bad)\nwith the attacker-supplied fake end e == snaptrace + snaptrace_len.\nWith snaptrace_len == 0xFFFFFFFF the bound check is trivially\nsatisfied, ri = p reads sizeof(struct ceph_mds_snap_realm) past\nthe legitimate msg->front buffer, and ri->num_snaps /\nri->num_prior_parent_snaps then drive further out-of-bounds\nreads of the encoded snap arrays.\n\nThe eleven msg_version >= 2 .. msg_version >= 12 decoder blocks\nabove the op switch each catch this OOB through their\nceph_decode_*_safe() / ceph_decode_need() helpers, but they sit\nbehind a hdr.version-gated if, so a malicious or compromised\nMDS that sets msg->hdr.version = 1 reaches the IMPORT path with\nno version-gated decoder having validated snap_trace_len. The\nshape has been present since ceph_handle_caps() was introduced.\n\nValidate snap_trace_len against the message front buffer before\nconsuming it, using the canonical ceph_decode_need() / ceph_has_room()\nhelper.  The helper bounds the length with subtraction (n <= end - p,\nguarded by end >= p) rather than pointer addition, so it is wrap-safe\nfor the attacker-controlled u32 length on 32-bit builds where\np + snap_trace_len could overflow the address space.  This matches the\nrest of the ceph decode path (e.g. the pool_ns_len check a few lines\nbelow), and the existing goto bad cleanup already covers this exit\npath.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/03b417afce19ee6b6e61f1bbbbebac924c9f36d1","https://git.kernel.org/stable/c/0c011137194036424e974677e0f1592e22a33d8c","https://git.kernel.org/stable/c/4dbc71bcaf9a30abf3920a4e2cc4ed33bba78c02","https://git.kernel.org/stable/c/71893c342a26bcff92eaab0b2b75d64aed19308a","https://git.kernel.org/stable/c/9081c71796724ffe96cba253f68fbe42363c5295"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:56:58.798400159+00:00"},"epss":{"cve":"CVE-2026-68160","score":0.00772,"percentile":0.55403,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}