{"id":"CVE-2026-80554","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Limit the number of channel program segments\n\nThe processing of channel programs, and the CCWs within them, is done\nrecursively","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Limit the number of channel program segments\n\nThe processing of channel programs, and the CCWs within them, is done\nrecursively. As such, there is an arb…","severity":"critical","cvss":9.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","cwe":["CWE-770"],"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9"],"published":"2026-08-26","updated":"2026-10-16","sourceUpdated":"2026-10-16T20:17:59.867","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80554","references":[{"url":"https://git.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80554.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-80554"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2524419"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80554"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80554"},{"url":"https://lore.kernel.org/linux-cve-announce/2026082608-CVE-2026-80554-aead@gregkh/T"}],"tags":["nvd","csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00196,"epssPercentile":0.09188,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T19:17:23.132592Z"},"scores":{"nvd":9.3,"vendor":5.5,"cna":9.3},"ingestedAt":"2026-10-16T19:46:24.315Z","slug":"CVE-2026-80554","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Limit the number of channel program segments\n\nThe processing of channel programs, and the CCWs within them, is done\nrecursively. As such, there is an arbitrary (but not architectural)\nlimit to the number of CCWs that can exist in a single channel program.\n\nThe vfio-ccw logic breaks these channel programs into segments whenever\nit encounters a Transfer-In-Channel (TIC) CCW, and the combined number\nof segments count towards the global limit. Impose an equivalent limit\nto the number of segments until such logic can be made non-recursive.\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** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80554.json)","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":51.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":230419,"id":"CVE-2026-80554","ts":1793134642074,"field":"cvss","old":"5.5","new":"9.3"},{"seq":230418,"id":"CVE-2026-80554","ts":1793134642074,"field":"severity","old":"medium","new":"critical"},{"seq":224133,"id":"CVE-2026-80554","ts":1792324946976,"field":"cvss","old":"9.3","new":"5.5"},{"seq":224132,"id":"CVE-2026-80554","ts":1792324946976,"field":"severity","old":"critical","new":"medium"}]}