{"id":"UBUNTU-CVE-2026-100888","details":"A weakness has been identified in Trusted Domain Project OpenDKIM up to 2.11.0. This affects the function dkim_canon_selecthdrs of the file libopendkim/dkim-canon.c of the component DKIM Signature Header Selection. Executing a manipulation of the argument h can lead to out-of-bounds write. The attack can be executed remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.","modified":"2026-09-30T21:41:53Z","published":"2026-09-28T00:16:00Z","upstream":["CVE-2026-100888"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-100888"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-100888"},{"type":"REPORT","url":"https://weitongli.com/share/opendkim-h-tag-oob-write.html"},{"type":"REPORT","url":"https://vuldb.com/cve/CVE-2026-100888"},{"type":"REPORT","url":"https://vuldb.com/submit/917015"},{"type":"REPORT","url":"https://vuldb.com/vuln/410837"},{"type":"REPORT","url":"https://vuldb.com/vuln/410837/cti"}],"affected":[{"package":{"name":"opendkim","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/opendkim?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.3-3build1"],"ecosystem_specific":{"binaries":[{"binary_version":"2.10.3-3build1","binary_name":"libopendkim10"},{"binary_name":"librbl1","binary_version":"2.10.3-3build1"},{"binary_name":"libvbr2","binary_version":"2.10.3-3build1"},{"binary_name":"opendkim","binary_version":"2.10.3-3build1"},{"binary_name":"opendkim-tools","binary_version":"2.10.3-3build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100888.json"}},{"package":{"name":"opendkim","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/opendkim?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11.0~alpha-10","2.11.0~alpha-11","2.11.0~alpha-11build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libopendkim11","binary_version":"2.11.0~alpha-11build1"},{"binary_version":"2.11.0~alpha-11build1","binary_name":"librbl1"},{"binary_version":"2.11.0~alpha-11build1","binary_name":"libvbr2"},{"binary_version":"2.11.0~alpha-11build1","binary_name":"opendkim"},{"binary_name":"opendkim-tools","binary_version":"2.11.0~alpha-11build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100888.json"}},{"package":{"name":"opendkim","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/opendkim?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11.0~alpha-12","2.11.0~alpha-13","2.11.0~alpha-14","2.11.0~beta2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libopendkim11","binary_version":"2.11.0~beta2-1"},{"binary_version":"2.11.0~beta2-1","binary_name":"librbl1"},{"binary_name":"libvbr2","binary_version":"2.11.0~beta2-1"},{"binary_name":"opendkim","binary_version":"2.11.0~beta2-1"},{"binary_version":"2.11.0~beta2-1","binary_name":"opendkim-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100888.json"}},{"package":{"name":"opendkim","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/opendkim?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11.0~beta2-4build1","2.11.0~beta2-5","2.11.0~beta2-6"],"ecosystem_specific":{"binaries":[{"binary_name":"libopendkim11","binary_version":"2.11.0~beta2-6"},{"binary_name":"librbl1","binary_version":"2.11.0~beta2-6"},{"binary_name":"libvbr2","binary_version":"2.11.0~beta2-6"},{"binary_name":"miltertest","binary_version":"2.11.0~beta2-6"},{"binary_version":"2.11.0~beta2-6","binary_name":"opendkim"},{"binary_version":"2.11.0~beta2-6","binary_name":"opendkim-tools"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100888.json"}},{"package":{"name":"opendkim","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/opendkim?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11.0~beta2-8","2.11.0~beta2-9","2.11.0~beta2-9build3","2.11.0~beta2-9build4"],"ecosystem_specific":{"binaries":[{"binary_version":"2.11.0~beta2-9build4","binary_name":"libopendkim11"},{"binary_version":"2.11.0~beta2-9build4","binary_name":"librbl1"},{"binary_version":"2.11.0~beta2-9build4","binary_name":"libvbr2"},{"binary_name":"miltertest","binary_version":"2.11.0~beta2-9build4"},{"binary_name":"opendkim","binary_version":"2.11.0~beta2-9build4"},{"binary_name":"opendkim-tools","binary_version":"2.11.0~beta2-9build4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100888.json"}},{"package":{"name":"opendkim","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/opendkim?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.11.0~beta2-9.2","2.11.0~beta2-9.2build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libopendkim11","binary_version":"2.11.0~beta2-9.2build1"},{"binary_version":"2.11.0~beta2-9.2build1","binary_name":"librbl1"},{"binary_version":"2.11.0~beta2-9.2build1","binary_name":"libvbr2"},{"binary_version":"2.11.0~beta2-9.2build1","binary_name":"miltertest"},{"binary_name":"opendkim","binary_version":"2.11.0~beta2-9.2build1"},{"binary_name":"opendkim-tools","binary_version":"2.11.0~beta2-9.2build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-100888.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P"},{"type":"Ubuntu","score":"medium"}]}