{"id":"UBUNTU-CVE-2026-50052","details":"In Vinyl Cache before 9.0.1 and Varnish Cache before 9.0.3, a deficiency in HTTP/2 request parsing can be exploited to launch a backend request desync attack (request smuggling), which in turn can be used for cache poisoning, authentication bypass, or possibly even information disclosure and manipulation. The attack vector only exists if HTTP/2 support is enabled by setting the feature parameter to contain +http2. HTTP/2 support is disabled by default.","modified":"2026-06-12T09:12:53.890855202Z","published":"2026-06-03T06:16:00Z","upstream":["CVE-2026-50052"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-50052"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-50052"}],"affected":[{"package":{"name":"varnish","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.4-1ubuntu1","3.0.4-1ubuntu2","3.0.5-1ubuntu2","3.0.5-2","3.0.5-2ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.0.5-2ubuntu0.1","binary_name":"libvarnishapi1"},{"binary_name":"varnish","binary_version":"3.0.5-2ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.3-1","4.1.0-1","4.1.0-2","4.1.1-1","4.1.1-1ubuntu0.2","4.1.1-1ubuntu0.2+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libvarnishapi1","binary_version":"4.1.1-1ubuntu0.2+esm1"},{"binary_name":"varnish","binary_version":"4.1.1-1ubuntu0.2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.0.0-7.1","5.2.1-1","5.2.1-1ubuntu0.1","5.2.1-1ubuntu0.1+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libvarnishapi1","binary_version":"5.2.1-1ubuntu0.1+esm1"},{"binary_version":"5.2.1-1ubuntu0.1+esm1","binary_name":"varnish"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.1.1-1","6.2.1-2","6.2.1-2ubuntu0.1~esm1","6.2.1-2ubuntu0.1~esm2","6.2.1-2ubuntu0.1","6.2.1-2ubuntu0.2","6.2.1-2ubuntu0.2+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libvarnishapi2","binary_version":"6.2.1-2ubuntu0.2+esm1"},{"binary_name":"varnish","binary_version":"6.2.1-2ubuntu0.2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.5.2-1","6.6.1-1","6.6.1-1ubuntu0.2","6.6.1-1ubuntu0.2+esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"libvarnishapi2","binary_version":"6.6.1-1ubuntu0.2+esm1"},{"binary_name":"varnish","binary_version":"6.6.1-1ubuntu0.2+esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.1.1-1.1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_version":"7.1.1-1.1ubuntu1","binary_name":"libvarnishapi3"},{"binary_name":"varnish","binary_version":"7.1.1-1.1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.7.0-1","7.7.0-2","7.7.0-3","7.7.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libvarnishapi3","binary_version":"7.7.3-1"},{"binary_name":"varnish","binary_version":"7.7.3-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}},{"package":{"name":"varnish","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/varnish?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["7.7.3-1","7.7.3-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libvarnishapi3","binary_version":"7.7.3-1build1"},{"binary_name":"varnish","binary_version":"7.7.3-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-50052.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/S:N/AU:N/R:A/V:D/RE:L/U:Green"},{"type":"Ubuntu","score":"medium"}]}