{"id":"CVE-2026-97906","title":"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 0xF…","summary":"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 0xF…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-125"],"vendor":"Linux","product":"Linux","affected":["Linux >= de462e5f10718517bacf2f84c8aa2804567ef7df < 4d45bc0f8cdf606d5409b5f64a8a6609f6520c03","Linux >= de462e5f10718517bacf2f84c8aa2804567ef7df < 8d4343a411eaa182d323ab5b149496416015f27d","Linux >= de462e5f10718517bacf2f84c8aa2804567ef7df < bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6","Linux >= de462e5f10718517bacf2f84c8aa2804567ef7df < 7812d6dab0698001e50e8c2f901e17da3eb6f429","Linux 32394df25d8e46935b442b429d74b37885c4f092","Linux >= 5.6.14 < 5.7","Linux 5.7"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:08.970","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97906","references":[{"url":"https://git.kernel.org/stable/c/4d45bc0f8cdf606d5409b5f64a8a6609f6520c03","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7812d6dab0698001e50e8c2f901e17da3eb6f429","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8d4343a411eaa182d323ab5b149496416015f27d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97906.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97906"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541104"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97906"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97906"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97906.mbox"},{"url":"https://git.kernel.org/stable/c/97be05f33f79342ea65d9b99c9ad07a93b8eef5a"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00217,"epssPercentile":0.12034,"cvssSource":"vendor","ingestedAt":"2026-09-25T11:06:38.893Z","slug":"CVE-2026-97906","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97906.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213532,"id":"CVE-2026-97906","ts":1790754763267,"field":"cvss","old":null,"new":"5.5"},{"seq":213531,"id":"CVE-2026-97906","ts":1790754763267,"field":"severity","old":"none","new":"medium"}]}