{"id":"UBUNTU-CVE-2026-14899","details":"The code to parse MIME headers for display when forwarding a message (if the setting to view all headers was enabled) had an off-by-one error, allowing a single byte to be read from the memory after the buffer for the headers, and potentially crashing Thunderbird. This vulnerability was fixed in Thunderbird 153 and Thunderbird 140.13.","modified":"2026-07-29T10:18:33.672270828Z","published":"2026-07-22T20:16:00Z","upstream":["CVE-2026-14899"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-14899"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-14899"},{"type":"REPORT","url":"https://www.mozilla.org/en-US/security/advisories/mfsa2026-72/#CVE-2026-14899"},{"type":"REPORT","url":"https://bugzilla.mozilla.org/show_bug.cgi?id=2046137"},{"type":"REPORT","url":"https://www.mozilla.org/security/advisories/mfsa2026-71/"},{"type":"REPORT","url":"https://www.mozilla.org/security/advisories/mfsa2026-72/"}],"affected":[{"package":{"name":"thunderbird","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/thunderbird?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:91.1.2+build1-0ubuntu1","1:91.3.0+build2-0ubuntu1","1:91.3.1+build1-0ubuntu1","1:91.3.2+build1-0ubuntu1","1:91.4.0+build1.1-0ubuntu1","1:91.4.0+build2-0ubuntu1","1:91.5.0+build1-0ubuntu1","1:91.5.1+build1-0ubuntu1","1:91.6.1+build1-0ubuntu1","1:91.7.0+build1-0ubuntu1","1:91.7.0+build2-0ubuntu1","1:91.8.0+build2-0ubuntu1","1:91.9.1+build1-0ubuntu0.22.04.1","1:91.11.0+build2-0ubuntu0.22.04.1","1:102.2.2+build1-0ubuntu0.22.04.1","1:102.4.2+build2-0ubuntu0.22.04.1","1:102.7.1+build2-0ubuntu0.22.04.1","1:102.8.0+build2-0ubuntu0.22.04.1","1:102.9.0+build1-0ubuntu0.22.04.1","1:102.10.0+build2-0ubuntu0.22.04.1","1:102.11.0+build1-0ubuntu0.22.04.1","1:102.13.0+build1-0ubuntu0.22.04.1","1:102.15.0+build1-0ubuntu0.22.04.1","1:102.15.1+build1-0ubuntu0.22.04.1","1:115.3.1+build1-0ubuntu0.22.04.2","1:115.4.1+build1-0ubuntu0.22.04.1","1:115.5.0+build1-0ubuntu0.22.04.1","1:115.6.0+build2-0ubuntu0.22.04.1","1:115.8.1+build1-0ubuntu0.22.04.1","1:115.9.0+build1-0ubuntu0.22.04.1","1:115.10.1+build1-0ubuntu0.22.04.1","1:115.11.0+build2-0ubuntu0.22.04.1","1:115.12.0+build3-0ubuntu0.22.04.1","1:115.13.0+build5-0ubuntu0.22.04.1","1:115.15.0+build1-0ubuntu0.22.04.1","1:115.16.0+build2-0ubuntu0.22.04.1","1:115.18.0+build1-0ubuntu0.22.04.1","1:128.12.0+build1-0ubuntu0.22.04.1","1:140.7.1+build1-0ubuntu0.22.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:140.7.1+build1-0ubuntu0.22.04.1","binary_name":"thunderbird"},{"binary_version":"1:140.7.1+build1-0ubuntu0.22.04.1","binary_name":"thunderbird-gnome-support"},{"binary_version":"1:140.7.1+build1-0ubuntu0.22.04.1","binary_name":"thunderbird-mozsymbols"},{"binary_version":"1:140.7.1+build1-0ubuntu0.22.04.1","binary_name":"xul-ext-calendar-timezones"},{"binary_name":"xul-ext-gdata-provider","binary_version":"1:140.7.1+build1-0ubuntu0.22.04.1"},{"binary_version":"1:140.7.1+build1-0ubuntu0.22.04.1","binary_name":"xul-ext-lightning"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-14899.json"}},{"package":{"name":"thunderbird","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/thunderbird?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:115.3.1+build1-0ubuntu1","1:115.4.1+build1-0ubuntu1","1:115.4.3+build1-0ubuntu1","1:115.5.0+build1-0ubuntu1","1:115.5.1+build1-0ubuntu1","1:115.5.2+build2-0ubuntu1","1:115.6.0+build1-0ubuntu1","1:115.6.0+build2-0ubuntu1","1:115.6.1+build1-0ubuntu1","1:115.8.0+build1-0ubuntu1","1:115.8.1+build1+snap2","1:115.8.1+build1+snap3","2:1snap1-0ubuntu1","2:1snap1-0ubuntu3"],"ecosystem_specific":{"binaries":[{"binary_version":"2:1snap1-0ubuntu3","binary_name":"thunderbird"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-14899.json"}},{"package":{"name":"thunderbird","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/thunderbird?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2:1snap1-0ubuntu3","2:1snap1-0ubuntu4","2:1snap1-0ubuntu5"],"ecosystem_specific":{"binaries":[{"binary_name":"thunderbird","binary_version":"2:1snap1-0ubuntu5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-14899.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}