{"id":"UBUNTU-CVE-2026-29013","details":"libcoap contains out-of-bounds read vulnerabilities in OSCORE Appendix B.2 CBOR unwrap handling where get_byte_inc() in src/oscore/oscore_cbor.c relies solely on assert() for bounds checking, which is removed in release builds compiled with NDEBUG. Attackers can send crafted CoAP requests with malformed OSCORE options or responses during OSCORE negotiation to trigger out-of-bounds reads during CBOR parsing and potentially cause out-of-bounds reads through integer wraparound in allocation size computation.","modified":"2026-06-04T12:45:25.894906669Z","published":"2026-04-17T22:16:00Z","upstream":["CVE-2026-29013"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-29013"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-29013"}],"affected":[{"package":{"name":"libcoap","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libcoap?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libcoap-1-0","binary_version":"4.1.2-1"},{"binary_name":"libcoap-1-0-bin","binary_version":"4.1.2-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}},{"package":{"name":"libcoap2","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libcoap2?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.0-2","4.2.1-1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.2.1-1","binary_name":"libcoap2"},{"binary_name":"libcoap2-bin","binary_version":"4.2.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}},{"package":{"name":"libcoap2","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libcoap2?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.1-1","4.2.1-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"4.2.1-1build1","binary_name":"libcoap2"},{"binary_name":"libcoap2-bin","binary_version":"4.2.1-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}},{"package":{"name":"libcoap3","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libcoap3?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.0-2","4.3.0-2build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libcoap3","binary_version":"4.3.0-2build1"},{"binary_version":"4.3.0-2build1","binary_name":"libcoap3-bin"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}},{"package":{"name":"libcoap3","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libcoap3?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.1-2","4.3.3-1","4.3.4-1","4.3.4-1.1build2","4.3.4-1.1build3","4.3.4-1.1build4"],"ecosystem_specific":{"binaries":[{"binary_name":"libcoap3-bin","binary_version":"4.3.4-1.1build4"},{"binary_version":"4.3.4-1.1build4","binary_name":"libcoap3t64"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}},{"package":{"name":"libcoap3","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libcoap3?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.4-1.1build4"],"ecosystem_specific":{"binaries":[{"binary_name":"libcoap3-bin","binary_version":"4.3.4-1.1build4"},{"binary_name":"libcoap3t64","binary_version":"4.3.4-1.1build4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}},{"package":{"name":"libcoap3","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libcoap3?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.4-1.1build4","4.3.5-1","4.3.5-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libcoap3-bin","binary_version":"4.3.5-2"},{"binary_name":"libcoap3t64","binary_version":"4.3.5-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-29013.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:H/SC:N/SI:N/SA:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}