{"id":"UBUNTU-CVE-2026-33555","details":"An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggling. The earliest affected version is 2.6.","modified":"2026-06-30T18:15:21.890241179Z","published":"2026-04-13T17:16:00Z","related":["USN-8208-1"],"upstream":["CVE-2026-33555"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-33555"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-33555"},{"type":"REPORT","url":"https://www.haproxy.com/documentation/haproxy-aloha/changelog/"},{"type":"REPORT","url":"https://www.mail-archive.com/haproxy@formilux.org/msg46752.html"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-8208-1"}],"affected":[{"package":{"name":"haproxy","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/haproxy?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.8.16-0ubuntu0.24.04.2"}]}],"versions":["2.6.15-1ubuntu2","2.8.5-1ubuntu1","2.8.5-1ubuntu2","2.8.5-1ubuntu3","2.8.5-1ubuntu3.1","2.8.5-1ubuntu3.2","2.8.5-1ubuntu3.3","2.8.5-1ubuntu3.4","2.8.15-0ubuntu0.24.04.1","2.8.16-0ubuntu0.24.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"haproxy","binary_version":"2.8.16-0ubuntu0.24.04.2"},{"binary_name":"vim-haproxy","binary_version":"2.8.16-0ubuntu0.24.04.2"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33555.json"}},{"package":{"name":"haproxy","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/haproxy?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.12-0ubuntu0.25.10.4"}]}],"versions":["3.0.8-1ubuntu1","3.0.8-1ubuntu1.1","3.0.10-1ubuntu1","3.0.10-1ubuntu2","3.0.10-1ubuntu3","3.0.12-0ubuntu0.25.10.1","3.0.12-0ubuntu0.25.10.3"],"ecosystem_specific":{"binaries":[{"binary_name":"haproxy","binary_version":"3.0.12-0ubuntu0.25.10.4"},{"binary_name":"vim-haproxy","binary_version":"3.0.12-0ubuntu0.25.10.4"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33555.json"}},{"package":{"name":"haproxy","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/haproxy?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.9-1ubuntu2.1"}]}],"versions":["3.0.10-1ubuntu3","3.2.9-1ubuntu1","3.2.9-1ubuntu2"],"ecosystem_specific":{"binaries":[{"binary_name":"haproxy","binary_version":"3.2.9-1ubuntu2.1"},{"binary_version":"3.2.9-1ubuntu2.1","binary_name":"vim-haproxy"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33555.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N"},{"type":"Ubuntu","score":"medium"}]}