{"id":"CVE-2026-90067","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: validate banner payload length\n\nWhen parsing the Ceph messenger v2 protocol banner, the `payload_len` field\nis decoded from the banner prefix","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: validate banner payload length\n\nWhen parsing the Ceph messenger v2 protocol banner, the `payload_len` field\nis decoded from the banner prefix. If a client send…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 279c0852999fd2384f4a88155091a99e81f96873","Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 6cf666e47f2b51d5a887ec8a3226cde951757d27","Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 3b2e62a7655d347a845a91155610ddae11daffc6","Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < c1b937ff24b19e69aa7fb1b0f46a74d4c9668692","Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < 6d1c6f228854aa89844fd0152d7ed7ac72a55e89","Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < c77633a9595658210a6e216a071e5a396a0835a7","Linux >= cd1a677cad994021b19665ed476aea63f5d54f31 < f374967fcdf04001c9b66df1c19106fa83cd91f7","Linux 5.11"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:17:40.537","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90067","references":[{"url":"https://git.kernel.org/stable/c/279c0852999fd2384f4a88155091a99e81f96873","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3b2e62a7655d347a845a91155610ddae11daffc6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6cf666e47f2b51d5a887ec8a3226cde951757d27","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6d1c6f228854aa89844fd0152d7ed7ac72a55e89","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c1b937ff24b19e69aa7fb1b0f46a74d4c9668692","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c77633a9595658210a6e216a071e5a396a0835a7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f374967fcdf04001c9b66df1c19106fa83cd91f7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.0067,"epssPercentile":0.50172,"ingestedAt":"2026-09-17T16:21:47.898Z","slug":"CVE-2026-90067","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: validate banner payload length\n\nWhen parsing the Ceph messenger v2 protocol banner, the `payload_len` field\nis decoded from the banner prefix. If a client sends a banner with a\n`payload_len` of 0, the kernel sets up a 0-length socket read. This\nviolates an invariant in the state machine, triggering a warning in\n`populate_in_iter()`:\n\n------------[ cut here ]------------\n!iov_iter_count(&con->v2.in_iter)\nWARNING: net/ceph/messenger_v2.c:3129 at populate_in_iter\nnet/ceph/messenger_v2.c:3129 [inline], CPU#1: kworker/1:3/5070\nWARNING: net/ceph/messenger_v2.c:3129 at ceph_con_v2_try_read+0x6634/0x6810\nnet/ceph/messenger_v2.c:3159, CPU#1: kworker/1:3/5070\n...\nCall Trace:\n <TASK>\n ceph_con_workfn+0x1f5/0x14a0 net/ceph/messenger.c:1575\n process_one_work kernel/workqueue.c:3322 [inline]\n process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405\n worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n </TASK>\n\nAccording to the msgr2 protocol specification, the banner payload is\nexpected to contain at least two 64-bit integers (`server_feat` and\n`server_req_feat`). Therefore, `payload_len` must be at least 16 bytes.\n\nFix this by adding a check in `process_banner_prefix()` to reject a\n`payload_len` smaller than 16 bytes. This prevents the 0-length read and\ncorrectly aborts the connection with a protocol error.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":207103,"id":"CVE-2026-90067","ts":1789757332147,"field":"cvss","old":null,"new":"7.5"},{"seq":207102,"id":"CVE-2026-90067","ts":1789757332147,"field":"severity","old":"none","new":"high"}]}