{"id":"UBUNTU-CVE-2021-43859","details":"XStream is an open source java library to serialize objects to XML and back again. Versions prior to 1.4.19 may allow a remote attacker to allocate 100% CPU time on the target system depending on CPU type or parallel execution of such a payload resulting in a denial of service only by manipulating the processed input stream. XStream 1.4.19 monitors and accumulates the time it takes to add elements to collections and throws an exception if a set threshold is exceeded. Users are advised to upgrade as soon as possible. Users unable to upgrade may set the NO_REFERENCE mode to prevent recursion. See GHSA-rmr5-cpv2-vgjf for further details on a workaround if an upgrade is not possible.","modified":"2026-05-20T16:06:30.153222078Z","published":"2022-02-01T12:15:00Z","upstream":["CVE-2021-43859"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-43859"},{"type":"REPORT","url":"https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf"},{"type":"REPORT","url":"https://x-stream.github.io/CVE-2021-43859.html"},{"type":"REPORT","url":"https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-43859"}],"affected":[{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.4-1","1.4.7-1","1.4.7-1ubuntu0.1","1.4.7-1ubuntu0.1+esm1","1.4.7-1ubuntu0.1+esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.7-1ubuntu0.1+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.8-1","1.4.8-1ubuntu0.1","1.4.8-1ubuntu0.1+esm1","1.4.8-1ubuntu0.1+esm2","1.4.8-1ubuntu0.1+esm3"],"ecosystem_specific":{"binaries":[{"binary_version":"1.4.8-1ubuntu0.1+esm3","binary_name":"libxstream-java"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.10-1","1.4.11.1-1~18.04","1.4.11.1-1~18.04.1","1.4.11.1-1~18.04.2","1.4.11.1-1+deb10u4build0.18.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.11.1-1+deb10u4build0.18.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.11.1-1","1.4.11.1-1ubuntu0.1","1.4.11.1-1ubuntu0.2","1.4.11.1-1ubuntu0.3"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.11.1-1ubuntu0.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.15-4","1.4.18-2","1.4.18-2ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.18-2ubuntu0.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.20-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.20-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.21-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.21-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.json"}},{"package":{"name":"libxstream-java","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libxstream-java?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.21-1"],"ecosystem_specific":{"binaries":[{"binary_name":"libxstream-java","binary_version":"1.4.21-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-43859.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:N/I:N/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}