{"id":"UBUNTU-CVE-2026-54901","details":"Oj (Optimized JSON) is a JSON parser and Object marshaller packaged as a Ruby gem. In versions prior to 3.17.2, Oj::Parser in usual mode does not mark array_class and hash_class references during garbage collection, leading to Use-After-Free. If GC runs after the class is assigned but before a parse, the class object is reclaimed, leaving the parser holding a dangling VALUE. The subsequent parse call dereferences the freed object, producing a segfault. This issue has been fixed in version 3.17.2.","modified":"2026-07-01T23:43:25.234904721Z","published":"2026-07-01T00:16:00Z","upstream":["CVE-2026-54901"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-54901"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-54901"},{"type":"REPORT","url":"https://github.com/ohler55/oj/security/advisories/GHSA-vwm4-62gf-x745"}],"affected":[{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.10-1","2.1.4-1","2.4.0-1","2.5.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"2.5.3-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.12.10-3","2.12.10-3build1","2.12.10-4","2.12.10-4build1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.12.10-4build1","binary_name":"ruby-oj"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.17.4-1","3.4.0-1","3.4.0-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.4.0-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.8.1-1","3.9.1-1","3.9.2-1","3.10.1-1","3.10.1-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.10.1-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.11.0-1","3.13.7-1","3.13.7-1build1","3.13.9-1","3.13.9-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.13.9-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.15.0-1","3.16.1-1","3.16.3-1","3.16.3-1build1","3.16.3-1build2"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.16.3-1build2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.16.3-1build3"],"ecosystem_specific":{"binaries":[{"binary_name":"ruby-oj","binary_version":"3.16.3-1build3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}},{"package":{"name":"ruby-oj","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/ruby-oj?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.16.3-1build3","3.16.12-1","3.16.15-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.16.15-1","binary_name":"ruby-oj"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-54901.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}