{"id":"CVE-2026-48840","aliases":["ALPINE-CVE-2026-48840","DEBIAN-CVE-2026-48840","EUVD-2026-33446","GHSA-wgrp-2w9f-fmvg","UBUNTU-CVE-2026-48840","USN-8353-1","USN-8382-1"],"status":"published","title":"Exim 4.88 before 4.99.4, in some proxy configurations, mishandles certain short payloads, leading...","description":"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.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00264,"percentile":0.18427,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-839"],"published":"2026-05-29T14:00:00Z","modified":"2026-11-03T06:33:05Z","fixes":[{"ecosystem":"Alpine:v3.23","package":"exim","fixed_in":["4.98.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"exim","fixed_in":["4.98.4-r0"],"sources":["osv"]},{"ecosystem":"Debian:12","package":"exim4","fixed_in":["4.96-15+deb12u10"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"exim4","fixed_in":["4.98.2-1+deb13u3"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"exim4","fixed_in":["4.99.3-2"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:16.04:LTS","package":"exim4","fixed_in":["4.86.2-2ubuntu2.6+esm9"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:18.04:LTS","package":"exim4","fixed_in":["4.90.1-1ubuntu1.10+esm6"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:20.04:LTS","package":"exim4","fixed_in":["4.93-13ubuntu1.12+esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:22.04:LTS","package":"exim4","fixed_in":["4.95-4ubuntu2.9"],"sources":["osv"]},{"ecosystem":"Ubuntu:24.04:LTS","package":"exim4","fixed_in":["4.97-4ubuntu4.6"],"sources":["osv"]},{"ecosystem":"Ubuntu:25.10","package":"exim4","fixed_in":["4.98.2-1ubuntu2.3"],"sources":["osv"]},{"ecosystem":"Ubuntu:26.04:LTS","package":"exim4","fixed_in":["4.99.1-1ubuntu1.3"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Alpine:v3.23","package":"exim","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.88"},{"fixed":"4.98.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"exim","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.88"},{"fixed":"4.98.4-r0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"exim4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.96-15+deb12u10"}]}],"versions":["4.96-15","4.96-15+deb12u1","4.96-15+deb12u2","4.96-15+deb12u3","4.96-15+deb12u4","4.96-15+deb12u5","4.96-15+deb12u6","4.96-15+deb12u7","4.96-15+deb12u8","4.96-15+deb12u9"]},{"source":"osv","ecosystem":"Debian:13","package":"exim4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.98.2-1+deb13u3"}]}],"versions":["4.98.2-1","4.98.2-1+deb13u1","4.98.2-1+deb13u2"]},{"source":"osv","ecosystem":"Debian:14","package":"exim4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.99.3-2"}]}],"versions":["4.98.2-1","4.98.2-1+hurd.1","4.98.2-2","4.99-1","4.99-2","4.99-3","4.99-4","4.99-4~bpo13+1","4.99-5","4.99-6","4.99-6~bpo13+1","4.99-7","4.99-7~bpo13+1","4.99.1-1","4.99.1-1~bpo13+1","4.99.1-2","4.99.1-3","4.99.1-4","4.99.1-5","4.99.1-6","4.99.2-1","4.99.2-1~bpo13+1","4.99.2-2","4.99.2-2~bpo13+1","4.99.3-1","4.99.3-2~bpo13+1","4.99~RC1-1","4.99~RC2-1","4.99~RC3-1","4.99~RC3-2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"exim4","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"]},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"exim4","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.82-3ubuntu2.4+esm9"}]}],"versions":["4.80-7ubuntu3","4.80-7ubuntu4","4.80-9ubuntu1","4.80-9ubuntu2","4.82-3ubuntu1","4.82-3ubuntu2","4.82-3ubuntu2.1","4.82-3ubuntu2.2","4.82-3ubuntu2.3","4.82-3ubuntu2.4","4.82-3ubuntu2.4+esm1","4.82-3ubuntu2.4+esm2","4.82-3ubuntu2.4+esm3","4.82-3ubuntu2.4+esm4","4.82-3ubuntu2.4+esm6","4.82-3ubuntu2.4+esm7","4.82-3ubuntu2.4+esm8"],"bundled":6},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"exim4","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"],"bundled":6},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"exim4","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"],"bundled":6},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"exim4","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"],"bundled":6}],"products":[{"vendor":"exim","product":"exim"}],"references":[{"url":"https://exim.org/static/doc/security/EXIM-Security-2026-05-19.1","tags":["Vendor Advisory"]},{"url":"https://www.openwall.com/lists/oss-security/2026/05/29/3","tags":["Mailing List","Mitigation","Third Party Advisory"]},{"url":"http://www.openwall.com/lists/oss-security/2026/05/29/3","tags":["Mailing List","Mitigation","Third Party Advisory"]},{"url":"https://lists.debian.org/debian-lts-announce/2026/06/msg00004.html"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48840"},{"url":"https://github.com/advisories/GHSA-wgrp-2w9f-fmvg"},{"url":"https://security.alpinelinux.org/vuln/CVE-2026-48840","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-48840","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-48840","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-48840","tags":["report"]},{"url":"https://www.exim.org/static/doc/security/EXIM-Security-2026-05-19.1/EXIM-Security-2026-05-19.1.txt","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-8353-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/notices/USN-8382-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2023-51766","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-40685","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-40686","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-40687","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-45185","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-48840","description":"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.","status":"published","published":"2026-05-30T01:50:42.637Z","modified":"2026-06-05T09:07:37.892Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-839"],"updated_at":"2026-11-02T13:50:49.872037Z"}],"euvd":[{"id":"EUVD-2026-33446","description":"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.","status":"published","published":"2026-05-30T01:50:42Z","modified":"2026-06-05T09:07:37Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T18:20:52.238484Z"}],"ghsa":[{"id":"GHSA-wgrp-2w9f-fmvg","title":"Exim 4.88 before 4.99.4, in some proxy configurations, mishandles certain short payloads, leading...","description":"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.","status":"published","published":"2026-05-30T03:30:20Z","modified":"2026-06-05T12:32:49Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"cwes":["CWE-839"],"updated_at":"2026-11-02T15:08:34.365209Z"}],"nvd":[{"id":"CVE-2026-48840","description":"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.","status":"published","published":"2026-05-30T02:16:19.79Z","modified":"2026-07-22T06:10:00.17Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-839"],"updated_at":"2026-11-02T14:12:21.635958Z"}],"osv":[{"id":"ALPINE-CVE-2026-48840","description":"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.","status":"published","published":"2026-05-30T02:16:19.79Z","modified":"2026-11-03T06:33:05.906708622Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-03T07:15:37.282377Z"},{"id":"DEBIAN-CVE-2026-48840","description":"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.","status":"published","published":"2026-05-30T02:16:19.79Z","modified":"2026-10-01T03:03:16.225839511Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:56.444225Z"},{"id":"UBUNTU-CVE-2026-48840","description":"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.","status":"published","published":"2026-05-29T14:00:00Z","modified":"2026-06-04T02:14:19.174228855Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","level":"medium"}],"updated_at":"2026-11-02T16:56:33.391918Z"},{"id":"USN-8353-1","title":"exim4 vulnerability","description":"Warisjeet Singh discovered that Exim with SUPPORT_PROXY enabled did not\nproperly handle memory before SMTP authentication. A remote attacker could\npossibly use this issue to obtain sensitive information.","status":"published","published":"2026-06-01T13:24:28Z","modified":"2026-06-01T19:14:33.859974809Z","updated_at":"2026-11-02T16:58:25.103481Z"},{"id":"USN-8382-1","title":"exim4 vulnerabilities","description":"Timo Longin discovered that Exim incorrectly handled certain SMTP messages\nin PIPELINING/CHUNKING configurations. A remote attacker could possibly use\nthis issue to perform SMTP smuggling. This issue only affected Ubuntu\n14.04 LTS. (CVE-2023-51766)\n\nIt was discovered that Exim incorrectly handled certain malformed JSON\ndata in headers. A remote attacker could possibly use this issue to crash\nExim, resulting in a denial of service, or execute arbitrary code. This\nissue only affected Ubuntu 20.04 LTS. (CVE-2026-40685)\n\nIt was discovered that Exim incorrectly handled certain malformed UTF-8\nheaders. A remote attacker could possibly use this issue to obtain\nsensitive information. This issue only affected Ubuntu 20.04 LTS.\n(CVE-2026-40686)\n\nIt was discovered that Exim incorrectly handled certain SPA resources.\nA remote attacker could possibly use this issue to crash Exim, resulting in\na denial of service, or obtain sensitive information. This issue only\naffected Ubuntu 20.04 LTS. (CVE-2026-40687)\n\nIt was discovered that Exim incorrectly handled certain CHUNKING\ntransfers in some GnuTLS configurations. A remote attacker could possibly\nuse this issue to crash Exim, resulting in a denial of service, or execute\narbitrary code. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-45185)\n\nWarisjeet Singh discovered that Exim incorrectly handled certain proxy\nconnections in builds with proxy support enabled. A remote attacker could\npossibly use this issue to obtain sensitive information. This issue only\naffected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.\n(CVE-2026-48840)","status":"published","published":"2026-06-03T16:29:23Z","modified":"2026-06-04T02:18:10.818665128Z","updated_at":"2026-11-02T16:58:25.103481Z"}]}}