{"cve":"CVE-2026-97906","nvd":{"published":"2026-09-25T11:17:17.517","modified":"2026-10-21T13:21:15.433","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbootconfig: Fix integer overflow in initrd size check\n\nSashiko reported that in get_boot_config_from_initrd(), a crafted initrd\nwith a huge bootconfig size (such as 0xFFFFFFFF) can cause the pointer\narithmetic:\n\n    data = ((void *)hdr) - size;\n\nto wrap around on 32-bit systems (or when pointer subtraction overflows).\nBecause data wraps around, the subsequent bounds check:\n\n    if ((unsigned long)data < initrd_start)\n\nevaluates to false, bypassing the check. The kernel then calls\nxbc_calc_checksum(data, size), which attempts to read 4GB of memory,\nhitting unmapped pages and triggering a fatal kernel page fault during\nearly boot. Furthermore, on 64-bit systems with an initrd > 4.29 GB, an\nunbounded 32-bit size can similarly bypass the initrd_start check.\n\nFix this by:\n1. Ensuring the initrd is at least large enough to contain the bootconfig\n   footer and verifying hdr is within the initrd bounds.\n2. Checking that size does not exceed XBC_DATA_MAX and does not exceed\n   the available space between initrd_start and hdr before performing\n   pointer subtraction.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/4d45bc0f8cdf606d5409b5f64a8a6609f6520c03","https://git.kernel.org/stable/c/7812d6dab0698001e50e8c2f901e17da3eb6f429","https://git.kernel.org/stable/c/8d4343a411eaa182d323ab5b149496416015f27d","https://git.kernel.org/stable/c/97be05f33f79342ea65d9b99c9ad07a93b8eef5a","https://git.kernel.org/stable/c/bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-97906","score":0.00217,"percentile":0.12002,"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."]}