{"id":"UBUNTU-CVE-2026-48840","details":"Exim 4.88 before 4.99.4, in some proxy configurations, mishandles certain short payloads, leading to disclosure of uninitialized stack memory values to a client.","modified":"2026-06-04T02:14:09.017788454Z","published":"2026-05-29T14:00:00Z","related":["USN-8353-1","USN-8382-1"],"upstream":["CVE-2026-48840"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-48840"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-48840"},{"type":"REPORT","url":"https://www.exim.org/static/doc/security/EXIM-Security-2026-05-19.1/EXIM-Security-2026-05-19.1.txt"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8353-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8382-1"}],"affected":[{"package":{"name":"exim4","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=esm-infra-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.86.2-2ubuntu2.6+esm9"}]}],"versions":["4.86-3ubuntu1","4.86-7ubuntu1","4.86-7ubuntu2","4.86-7ubuntu3","4.86.2-2ubuntu1","4.86.2-2ubuntu2","4.86.2-2ubuntu2.1","4.86.2-2ubuntu2.2","4.86.2-2ubuntu2.3","4.86.2-2ubuntu2.4","4.86.2-2ubuntu2.5","4.86.2-2ubuntu2.6","4.86.2-2ubuntu2.6+esm1","4.86.2-2ubuntu2.6+esm2","4.86.2-2ubuntu2.6+esm4","4.86.2-2ubuntu2.6+esm5","4.86.2-2ubuntu2.6+esm6","4.86.2-2ubuntu2.6+esm7","4.86.2-2ubuntu2.6+esm8"],"ecosystem_specific":{"binaries":[{"binary_name":"exim4","binary_version":"4.86.2-2ubuntu2.6+esm9"},{"binary_version":"4.86.2-2ubuntu2.6+esm9","binary_name":"exim4-base"},{"binary_version":"4.86.2-2ubuntu2.6+esm9","binary_name":"exim4-config"},{"binary_version":"4.86.2-2ubuntu2.6+esm9","binary_name":"exim4-daemon-heavy"},{"binary_version":"4.86.2-2ubuntu2.6+esm9","binary_name":"exim4-daemon-light"},{"binary_name":"eximon4","binary_version":"4.86.2-2ubuntu2.6+esm9"}],"availability":"Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.json"}},{"package":{"name":"exim4","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=esm-infra%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.90.1-1ubuntu1.10+esm6"}]}],"versions":["4.89-5ubuntu1","4.89-9ubuntu1","4.89-9ubuntu2","4.89-9ubuntu3","4.89-9ubuntu4","4.90.1-1ubuntu1","4.90.1-1ubuntu1.1","4.90.1-1ubuntu1.2","4.90.1-1ubuntu1.3","4.90.1-1ubuntu1.4","4.90.1-1ubuntu1.5","4.90.1-1ubuntu1.8","4.90.1-1ubuntu1.9","4.90.1-1ubuntu1.10","4.90.1-1ubuntu1.10+esm1","4.90.1-1ubuntu1.10+esm2","4.90.1-1ubuntu1.10+esm3","4.90.1-1ubuntu1.10+esm4","4.90.1-1ubuntu1.10+esm5"],"ecosystem_specific":{"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro","binaries":[{"binary_version":"4.90.1-1ubuntu1.10+esm6","binary_name":"exim4"},{"binary_version":"4.90.1-1ubuntu1.10+esm6","binary_name":"exim4-base"},{"binary_version":"4.90.1-1ubuntu1.10+esm6","binary_name":"exim4-config"},{"binary_name":"exim4-daemon-heavy","binary_version":"4.90.1-1ubuntu1.10+esm6"},{"binary_version":"4.90.1-1ubuntu1.10+esm6","binary_name":"exim4-daemon-light"},{"binary_version":"4.90.1-1ubuntu1.10+esm6","binary_name":"eximon4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.json"}},{"package":{"name":"exim4","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=esm-infra%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.93-13ubuntu1.12+esm1"}]}],"versions":["4.92.1-1ubuntu3","4.92.1-1ubuntu4","4.93~RC2-1ubuntu1","4.93-9ubuntu1","4.93-11ubuntu1","4.93-12ubuntu1","4.93-13ubuntu1","4.93-13ubuntu1.1","4.93-13ubuntu1.5","4.93-13ubuntu1.6","4.93-13ubuntu1.7","4.93-13ubuntu1.8","4.93-13ubuntu1.9","4.93-13ubuntu1.10","4.93-13ubuntu1.11","4.93-13ubuntu1.12"],"ecosystem_specific":{"binaries":[{"binary_name":"exim4","binary_version":"4.93-13ubuntu1.12+esm1"},{"binary_name":"exim4-base","binary_version":"4.93-13ubuntu1.12+esm1"},{"binary_version":"4.93-13ubuntu1.12+esm1","binary_name":"exim4-config"},{"binary_name":"exim4-daemon-heavy","binary_version":"4.93-13ubuntu1.12+esm1"},{"binary_name":"exim4-daemon-light","binary_version":"4.93-13ubuntu1.12+esm1"},{"binary_name":"eximon4","binary_version":"4.93-13ubuntu1.12+esm1"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.json"}},{"package":{"name":"exim4","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.95-4ubuntu2.9"}]}],"versions":["4.94.2-7ubuntu2","4.95-2ubuntu2","4.95-4ubuntu1","4.95-4ubuntu2","4.95-4ubuntu2.1","4.95-4ubuntu2.2","4.95-4ubuntu2.3","4.95-4ubuntu2.4","4.95-4ubuntu2.5","4.95-4ubuntu2.6","4.95-4ubuntu2.7","4.95-4ubuntu2.8"],"ecosystem_specific":{"availability":"No subscription required","binaries":[{"binary_version":"4.95-4ubuntu2.9","binary_name":"exim4"},{"binary_name":"exim4-base","binary_version":"4.95-4ubuntu2.9"},{"binary_name":"exim4-config","binary_version":"4.95-4ubuntu2.9"},{"binary_name":"exim4-daemon-heavy","binary_version":"4.95-4ubuntu2.9"},{"binary_name":"exim4-daemon-light","binary_version":"4.95-4ubuntu2.9"},{"binary_version":"4.95-4ubuntu2.9","binary_name":"eximon4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.json"}},{"package":{"name":"exim4","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.97-4ubuntu4.6"}]}],"versions":["4.96-17ubuntu2","4.96-17ubuntu2.1","4.97-3ubuntu1","4.97-4ubuntu1","4.97-4ubuntu3","4.97-4ubuntu4","4.97-4ubuntu4.1","4.97-4ubuntu4.2","4.97-4ubuntu4.3","4.97-4ubuntu4.4","4.97-4ubuntu4.5"],"ecosystem_specific":{"binaries":[{"binary_name":"exim4","binary_version":"4.97-4ubuntu4.6"},{"binary_name":"exim4-base","binary_version":"4.97-4ubuntu4.6"},{"binary_name":"exim4-config","binary_version":"4.97-4ubuntu4.6"},{"binary_name":"exim4-daemon-heavy","binary_version":"4.97-4ubuntu4.6"},{"binary_name":"exim4-daemon-light","binary_version":"4.97-4ubuntu4.6"},{"binary_name":"eximon4","binary_version":"4.97-4ubuntu4.6"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.json"}},{"package":{"name":"exim4","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.98.2-1ubuntu2.3"}]}],"versions":["4.98.1-1ubuntu2","4.98.2-1ubuntu1","4.98.2-1ubuntu2","4.98.2-1ubuntu2.1","4.98.2-1ubuntu2.2"],"ecosystem_specific":{"binaries":[{"binary_name":"exim4","binary_version":"4.98.2-1ubuntu2.3"},{"binary_version":"4.98.2-1ubuntu2.3","binary_name":"exim4-base"},{"binary_version":"4.98.2-1ubuntu2.3","binary_name":"exim4-config"},{"binary_name":"exim4-daemon-heavy","binary_version":"4.98.2-1ubuntu2.3"},{"binary_version":"4.98.2-1ubuntu2.3","binary_name":"exim4-daemon-light"},{"binary_version":"4.98.2-1ubuntu2.3","binary_name":"eximon4"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.json"}},{"package":{"name":"exim4","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/exim4?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.99.1-1ubuntu1.3"}]}],"versions":["4.98.2-1ubuntu2","4.99-4ubuntu1","4.99.1-1ubuntu1","4.99.1-1ubuntu1.1","4.99.1-1ubuntu1.2"],"ecosystem_specific":{"binaries":[{"binary_version":"4.99.1-1ubuntu1.3","binary_name":"exim4"},{"binary_version":"4.99.1-1ubuntu1.3","binary_name":"exim4-base"},{"binary_name":"exim4-config","binary_version":"4.99.1-1ubuntu1.3"},{"binary_version":"4.99.1-1ubuntu1.3","binary_name":"exim4-daemon-heavy"},{"binary_name":"exim4-daemon-light","binary_version":"4.99.1-1ubuntu1.3"},{"binary_name":"eximon4","binary_version":"4.99.1-1ubuntu1.3"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48840.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:L/I:N/A:N"},{"type":"Ubuntu","score":"medium"}]}