{"cve":"CVE-2026-52957","nvd":{"published":"2026-06-24T17:17:05.900","modified":"2026-10-19T20:18:50.930","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Fix potential null-ptr-deref in decode_choose_args()\n\nA message of type CEPH_MSG_OSD_MAP contains an OSD map that itself\ncontains a CRUSH map. When decoding this CRUSH map in crush_decode(), an\narray of max_buckets CRUSH buckets is decoded, where some indices may\nnot refer to actual buckets and are therefore set to NULL. The received\nCRUSH map may optionally contain choose_args that get decoded in\ndecode_choose_args(). When decoding a crush_choose_arg_map, a series of\nchoose_args for different buckets is decoded, with the bucket_index\nbeing read from the incoming message. It is only checked that the bucket\nindex does not exceed max_buckets, but not that it doesn't point to an\nindex with a NULL bucket. If a (potentially corrupted) message contains\na crush_choose_arg_map including such a bucket_index, a null pointer\ndereference may occur in the subsequent processing when attempting to\naccess the bucket with the given index.\n\nThis patch fixes the issue by extending the affected check. Now, it is\nonly attempted to access the bucket if it is not NULL.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/28b0a2ab8c82d0bbdeb8013029c67c978ce6e4bf","https://git.kernel.org/stable/c/301286c0ccd37d66b0e40786fd35a4f19cdbd88a","https://git.kernel.org/stable/c/312ec973efac0efb9b9ed64214235910e9ecbaa8","https://git.kernel.org/stable/c/7169f326a23d0f547fcd90e68b72fd387622e126","https://git.kernel.org/stable/c/a20e16ebfe2fa65348eb4b2dc7deac330ce03e9c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-52957","score":0.00523,"percentile":0.44124,"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."]}