{"id":"CVE-2026-80580","state":"PUBLISHED","title":"fbdev: bound mode sysfs output to the sysfs buffer","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: bound mode sysfs output to the sysfs buffer\n\nmode_string() uses snprintf() which can return a value larger than the\nremaining buffer space. show_modes() accumulates the return value into i\nwithout checking whether i has reached PAGE_SIZE, causing the offset to\nadvance past the sysfs buffer if the modelist is long enough.\n\nAdd a size parameter to mode_string() and use scnprintf() to return\nonly the bytes actually written. Add an early return when offset\nalready exceeds the buffer. In show_modes(), stop accumulating once\nthe buffer is full.","publishedAt":"2026-08-26T14:37:37.917Z","updatedAt":"2026-10-16T19:26:28.187Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"873a1aa15c313263f2e18b38cf525623cc4fabf6","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"d15d51fb26e830af58f3f21964f1c09c239077ea","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fbsysfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"7.1.10","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fbsysfs.c"]}],"references":["https://git.kernel.org/stable/c/873a1aa15c313263f2e18b38cf525623cc4fabf6","https://git.kernel.org/stable/c/d15d51fb26e830af58f3f21964f1c09c239077ea"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80580.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80580","state":"PUBLISHED","datePublished":"2026-08-26T14:37:37.917Z","dateUpdated":"2026-10-16T19:26:28.187Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.769Z"},"containers":{"cna":{"title":"fbdev: bound mode sysfs output to the sysfs buffer","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: bound mode sysfs output to the sysfs buffer\n\nmode_string() uses snprintf() which can return a value larger than the\nremaining buffer space. show_modes() accumulates the return value into i\nwithout checking whether i has reached PAGE_SIZE, causing the offset to\nadvance past the sysfs buffer if the modelist is long enough.\n\nAdd a size parameter to mode_string() and use scnprintf() to return\nonly the bytes actually written. Add an early return when offset\nalready exceeds the buffer. In show_modes(), stop accumulating once\nthe buffer is full."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"873a1aa15c313263f2e18b38cf525623cc4fabf6","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"d15d51fb26e830af58f3f21964f1c09c239077ea","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fbsysfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"7.1.10","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/video/fbdev/core/fbsysfs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/873a1aa15c313263f2e18b38cf525623cc4fabf6"},{"url":"https://git.kernel.org/stable/c/d15d51fb26e830af58f3f21964f1c09c239077ea"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only by a local read(2) on /sys/class/graphics/fbN/modes, which flows through sysfs/kernfs into show_modes(); there is no network, adjacent-network, or physical-device packet path to this framebuffer sysfs handler.\nAC:L - Once the framebuffer modelist is long enough to fill PAGE_SIZE, snprintf's oversized return value deterministically pushes the offset past the buffer and subsequent writes use a wrapped huge size; an attacker can also grow the list via repeated FBIOPUT_VSCREENINFO or a privileged store_modes write.\nPR:L - The modes sysfs attribute is DEVICE_ATTR_RW with mode 0644, so any unprivileged local user can open and read it without capabilities; only populating an unusually long modelist may require root or membership in the video group for /dev/fb0 ioctl access.\nUI:N - Exploitation requires only the attacker reading the modes sysfs file themselves; no separate victim action such as mounting a filesystem or opening a file is needed.\nS:U - The overflow corrupts kernel heap memory within the same OS security boundary and can enable local privilege escalation, but it does not cross VM, IOMMU, or sandbox isolation boundaries.\nC:H - Writing past the PAGE_SIZE sysfs seq_file buffer is an out-of-bounds kernel heap write; once the offset exceeds PAGE_SIZE the remaining-length underflow gives snprintf an enormous size, corrupting adjacent kmalloc objects and enabling information disclosure.\nI:H - The unchecked offset advance causes repeated out-of-bounds writes into kernel heap memory beyond the sysfs buffer, a memory-corruption primitive that can be leveraged for arbitrary kernel writes or control-flow hijacking.\nA:H - Corrupting heap objects adjacent to the sysfs read buffer can trigger immediate kernel oops/panic or later crashes when those objects are used, satisfying High availability impact for kernel memory corruption."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-27T05:02:01.683Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-80580","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T19:17:49.806822Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T19:26:28.187Z"}}]}}}