{"id":"UBUNTU-CVE-2026-55392","details":"NILFS utilities through 2.3.0, fixed in commit 26efb5d, nilfs_sb_is_valid() function fails to validate s_log_block_size field in NILFS2 superblock before bit-shift operations. Attackers supplying crafted NILFS2 images trigger undefined behavior through oversized shifts or out-of-memory conditions, crashing tools like nilfs-tune and dumpseg.","modified":"2026-06-24T11:02:00.968818231Z","published":"2026-06-18T19:16:00Z","upstream":["CVE-2026-55392"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-55392"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-55392"},{"type":"REPORT","url":"https://github.com/nilfs-dev/nilfs-utils/issues/26"}],"affected":[{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.3-2"],"ecosystem_specific":{"binaries":[{"binary_version":"2.2.3-2","binary_name":"nilfs-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}},{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.6-1"],"ecosystem_specific":{"binaries":[{"binary_name":"nilfs-tools","binary_version":"2.2.6-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}},{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.7-1","2.2.8-1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.2.8-1","binary_name":"nilfs-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}},{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.8-1"],"ecosystem_specific":{"binaries":[{"binary_name":"nilfs-tools","binary_version":"2.2.8-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}},{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.9-1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.2.9-1","binary_name":"nilfs-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}},{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.11-2"],"ecosystem_specific":{"binaries":[{"binary_name":"nilfs-tools","binary_version":"2.2.11-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}},{"package":{"name":"nilfs-tools","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/nilfs-tools?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.11-2","2.2.11-2build1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.2.11-2build1","binary_name":"nilfs-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-55392.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}