{"id":"CVE-2026-98726","kind":"vulnerability","aliases":["CVE-2026-98726"],"related":[],"title":"Linux kernel: NVMe multipath ANA log parsing can read past its buffer","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvme-multipath: fix underflow in ANA log bounds checks\n\nThe number of ANA groups advertised through Identify Controller sizes the\nANA log buffer. The ANA log header and group descriptors independently\nsupply the number of groups and namespace IDs to parse.\n\nBoth bounds checks subtract an untrusted object size from ana_log_size\nbefore comparing the current offset. If the object is larger than the\nbuffer, the size_t subtraction underflows and lets the parser read beyond\nana_log_buf.\n\nCheck the current offset before the first subtraction and compare each\nobject size with the remaining buffer instead. This rejects inconsistent\nANA data before dereferencing a truncated group descriptor or walking an\noversized namespace ID array.","summary":"The Linux kernel's NVMe multipath code subtracts an untrusted object size from the ANA log buffer length, so an oversized value underflows and the parser reads beyond the buffer. The sources do not say what an attacker gets beyond an out-of-bounds read.","severity":"unknown","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["kernel","linux","nvme","runtime","self-hosted","storage"],"not_affected_if":["no-nvme-multipath","no-nvme-storage"],"how_to_check":"- Run `uname -r` and compare against the fixed kernel builds listed in the NVD entry.\n- Check whether the `nvme_core` module is loaded with `lsmod | grep nvme` and whether multipath is in use (`cat /sys/module/nvme_core/parameters/multipath`).","fix":"- Update the Linux kernel to a build that includes the upstream nvme-multipath ANA log bounds fix (version unknown from the sources; see the NVD entry).","status":"open","published_at":"2026-10-18T16:17:26+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","triaged_at":"2026-10-25T05:17:20+00:00","updated_at":"2026-10-25T05:17:20+00:00","category":"runtime","confidence":0.5,"triage":{"at":"2026-10-25T05:17:20Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Linux kernel to a build that includes the upstream nvme-multipath ANA log bounds fix (version unknown from the sources; see the NVD entry).","reach":"unknown","title":"Linux kernel: NVMe multipath ANA log parsing can read past its buffer","impact":"medium","summary":"The Linux kernel's NVMe multipath code subtracts an untrusted object size from the ANA log buffer length, so an oversized value underflows and the parser reads beyond the buffer. The sources do not say what an attacker gets beyond an out-of-bounds read.","category":"runtime","nicknames":[],"who_cares":["linux","kernel","nvme","storage","self-hosted"],"confidence":0.5,"needs_auth":"unknown","worst_case":"unknown; out-of-bounds read in kernel memory is possible","analyst_note":"Check the NVD entry and the upstream kernel commit for affected version ranges, CVSS score, and whether the flaw is reachable from a remote storage target or only a local one.","how_to_check":"- Run `uname -r` and compare against the fixed kernel builds listed in the NVD entry.\n- Check whether the `nvme_core` module is loaded with `lsmod | grep nvme` and whether multipath is in use (`cat /sys/module/nvme_core/parameters/multipath`).","needs_analyst":true,"not_affected_if":["no-nvme-multipath","no-nvme-storage"],"who_is_affected":"Systems running the Linux kernel with NVMe storage that uses native NVMe multipath, where the ANA log is read from a storage controller. Hosts without NVMe multipath or without NVMe-oF attached storage are unlikely to parse ANA data at all. The sources do not say which kernel versions are affected.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000672,"input_tokens":3481,"output_tokens":648,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':14A,17A '-98726':15A,18A 'advertis':98C 'ana':5A,41B,89C,96C,104C,108C,134C,161C,185C 'array':199C 'attack':64B 'beyond':54B,66B,160C 'bound':71B,91C,126C 'buf':163C 'buffer':12A,43B,56B,106C,149C,180C 'check':92C,127C,164C 'code':33B 'compar':138C,173C 'control':101C 'current':140C,166C 'cve':13A,16A 'data':186C 'dereferenc':188C 'descriptor':113C,192C 'first':170C 'fix':86C 'follow':78C 'get':65B 'group':97C,112C,119C,191C 'header':110C 'host':25B 'id':122C,198C 'identifi':100C 'inconsist':184C 'independ':114C 'instead':181C 'kernel':2A,19B,29B,76C 'larger':146C 'length':44B 'let':156C 'linux':1A,20B,28B,75C 'log':6A,42B,90C,105C,109C,135C,162C 'multipath':4A,32B,85C 'namespac':121C,197C 'number':94C,117C 'nvme':3A,21B,31B,84C 'nvme-multipath':83C 'object':37B,131C,144C,175C 'offset':141C,167C 'out-of-bound':68B 'overs':47B,196C 'pars':7A,124C 'parser':52B,158C 'past':10A 'read':9A,53B,72B,159C 'reject':183C 'remain':179C 'resolv':82C 'runtim':22B 'say':61B 'self':24B 'self-host':23B 'size':38B,102C,132C,136C,151C,176C 'sourc':58B 'storag':26B 'subtract':34B,128C,153C,171C 'suppli':115C 'truncat':190C 'underflow':49B,87C,154C 'untrust':36B,130C 'valu':48B 'vulner':79C 'walk':194C","nicknames":[],"mitigations":[],"who_affected":"Systems running the Linux kernel with NVMe storage that uses native NVMe multipath, where the ANA log is read from a storage controller. Hosts without NVMe multipath or without NVMe-oF attached storage are unlikely to parse ANA data at all. The sources do not say which kernel versions are affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-18T16:17:26+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-98726","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98726","severity":null,"published_at":"2026-10-18T16:17:26+00:00","modified_at":"2026-10-21T13:21:40+00:00","first_seen_at":"2026-10-23T21:57:16+00:00","fetched_at":"2026-10-23T22:28:56+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}