{"cve":{"cve_id":"CVE-2021-43859","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.07934,"epss_percentile":0.94664,"epss_as_of":"2026-10-15","description":"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.","published_at":"2022-02-01T12:08:57Z","last_modified_at":null,"cvss_v3_score":7.5,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"poc","ssvc_automatable":true,"ssvc_technical_impact":"partial","cwes":["CWE-400"],"nvd_references":["https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf","https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846","https://x-stream.github.io/CVE-2021-43859.html","http://www.openwall.com/lists/oss-security/2022/02/09/1","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XODFRE2ZL64FICBJDOPWOLPTSSAI4U7X/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VACQYG356OHUTD5WQGAQ4L2TTFTAV3SJ/","https://lists.debian.org/debian-lts-announce/2022/02/msg00018.html","https://www.oracle.com/security-alerts/cpuapr2022.html","https://www.oracle.com/security-alerts/cpujul2022.html"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:16:22.449546Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"x-stream","vendor_name":"x-stream","product_slug":"xstream","product_name":"xstream","version_start":"< 1.4.19","version_start_inclusive":true,"version_end":"< 1.4.19","version_end_inclusive":true,"cpe23_uri":"cve5:x-stream:xstream:< 1.4.19:< 1.4.19"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/x-stream/xstream/security/advisories/GHSA-rmr5-cpv2-vgjf","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/x-stream/xstream/commit/e8e88621ba1c85ac3b8620337dd672e0c0c3a846","source_type":"PATCH","tags":["patch"]},{"url":"https://x-stream.github.io/CVE-2021-43859.html","source_type":"MISC","tags":[]},{"url":"http://www.openwall.com/lists/oss-security/2022/02/09/1","source_type":"MAILING_LIST","tags":["mailing-list"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XODFRE2ZL64FICBJDOPWOLPTSSAI4U7X/","source_type":"MAILING_LIST","tags":["mailing-list"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VACQYG356OHUTD5WQGAQ4L2TTFTAV3SJ/","source_type":"MAILING_LIST","tags":["mailing-list"]},{"url":"https://lists.debian.org/debian-lts-announce/2022/02/msg00018.html","source_type":"MAILING_LIST","tags":["mailing-list"]},{"url":"https://www.oracle.com/security-alerts/cpuapr2022.html","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://www.oracle.com/security-alerts/cpujul2022.html","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2022-02-01T12:08:57Z","label":"CVE published","source":null},{"type":"ssvc_changed","at":"2026-06-24T00:31:47.654584Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:47.654584Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-24T00:31:47.654584Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:47.654584Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:47.654584Z","label":"CVSS score revised","source":"vulnrichment"},{"type":"cvss_changed","at":"2026-06-24T00:31:47.654584Z","label":"CVSS score revised","source":"vulnrichment"}]}