{"id":"CVE-2020-26259","published":"2020-12-16T01:05:16Z","modified":"2026-10-07T18:40:59Z","title":"XStream is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling","vendor":"x-stream","product":"xstream","tier":"core","eol":null,"affectedVersions":[{"vendor":"x-stream","product":"xstream","versions":["< 1.4.15"]}],"description":{"text":"XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling. The vulnerability may allow a remote attacker to delete arbitrary know files on the host as log as the executing process has sufficient rights only by manipulating the processed input stream. If you rely on XStream's default blacklist of the Security Framework, you will have to use at least version 1.4.15. The reported vulnerability does not exist running Java 15 or higher. No user is affected, who followed the recommendation to setup XStream's Security Framework with a whitelist! Anyone relying on XStream's default blacklist can immediately switch to a whilelist for the allowed types to avoid the vulnerability. Users of XStream 1.4.14 or below who still want to use XStream default blacklist can use a workaround described in more detailed in the referenced advisories.","provenance":"source","from":"CVE.org"},"summary":{"text":"XStream, a Java library for serializing objects to XML and back, contains an arbitrary file deletion flaw during unmarshalling that affects versions before 1.4.15 and is reachable through the processed input stream. A remote attacker who can supply crafted input to an affected deserialization path can delete arbitrary files on the host, provided the executing process has sufficient rights and the attack is not possible on Java 15 or higher, nor where a whitelist-based Security Framework is configured.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:13:27Z"},"cvss":{"score":6.8,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N","provenance":"source","from":"CVE.org CNA"},"epss":{"score":0.82392,"percentile":0.99663,"date":"2026-10-31","provenance":"source"},"kev":null,"vulncheckKev":null,"exploited":false,"otx":null,"cwes":[{"id":"CWE-78","name":"Improper Neutralization of Special Elements used in an OS Command"}],"references":[{"url":"https://github.com/x-stream/xstream/security/advisories/GHSA-jfvx-7wrx-43fh","tags":["x_refsource_CONFIRM"]},{"url":"https://x-stream.github.io/CVE-2020-26259.html","tags":["x_refsource_MISC"]},{"url":"https://lists.apache.org/thread.html/r97993e3d78e1f5389b7b172ba9f308440830ce5f051ee62714a0aa34%40%3Ccommits.struts.apache.org%3E","tags":["mailing-list","x_refsource_MLIST"]},{"url":"https://lists.debian.org/debian-lts-announce/2020/12/msg00042.html","tags":["mailing-list","x_refsource_MLIST"]},{"url":"https://www.debian.org/security/2021/dsa-4828","tags":["vendor-advisory","x_refsource_DEBIAN"]},{"url":"https://security.netapp.com/advisory/ntap-20210409-0005/","tags":["x_refsource_CONFIRM"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/22KVR6B5IZP3BGQ3HPWIO2FWWCKT3DHP/","tags":["vendor-advisory","x_refsource_FEDORA"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QGXIU3YDPG6OGTDHMBLAFN7BPBERXREB/","tags":["vendor-advisory","x_refsource_FEDORA"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PVPHZA7VW2RRSDCOIPP2W6O5ND254TU7/","tags":["vendor-advisory","x_refsource_FEDORA"]}],"techniques":[],"reports":[],"affected":[{"ecosystem":"Maven","package":"com.thoughtworks.xstream:xstream","vulnerableRanges":["<1.4.15"],"patched":["1.4.15"],"from":["GHSA-jfvx-7wrx-43fh"],"provenance":"source"}],"advisories":[{"id":"GHSA-jfvx-7wrx-43fh","url":"https://github.com/advisories/GHSA-jfvx-7wrx-43fh","severity":"MODERATE","ecosystem":"Maven","package":"com.thoughtworks.xstream:xstream","vulnerableRanges":["<1.4.15"],"patched":["1.4.15"],"provenance":"source","from":"GHSA"}],"euvd":{"id":"EUVD-2020-1497","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-1497","exploited":false,"exploitedSince":null,"provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":2,"skipped":1,"earliest":"2020-12-13","earliestUrl":"https://github.com/jas502n/CVE-2020-26259","repos":[{"name":"jas502n/CVE-2020-26259","url":"https://github.com/jas502n/CVE-2020-26259","stars":25,"created":"2020-12-13"},{"name":"Al1ex/CVE-2020-26259","url":"https://github.com/Al1ex/CVE-2020-26259","stars":1,"created":"2021-01-22"}]},"first":{"date":"2020-12-13","source":"PoC-in-GitHub","url":"https://github.com/jas502n/CVE-2020-26259"},"provenance":"source"},"exploitRefs":[],"flow":[],"timeline":[{"date":"2020-12-13","kind":"exploit-public","label":"First public exploit: PoC-in-GitHub","url":"https://github.com/jas502n/CVE-2020-26259","provenance":"source"},{"date":"2020-12-16","kind":"published","label":"Published (CVE.org)","url":"https://www.cve.org/CVERecord?id=CVE-2020-26259","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":"PoC-in-GitHub","daysToKev":null},"priority":{"score":29.7,"factors":[{"name":"In a KEV catalog","points":0.0,"detail":"not listed"},{"name":"Recent KEV listing","points":0.0,"detail":"not listed"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.93,"detail":"percentile 0.9966"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"2 PoC-in-GitHub repos"},{"name":"Mentioned in OTX pulses","points":0.0,"detail":"0 pulses"},{"name":"CVSS severity","points":4.76,"detail":"base score 6.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]},"lineage":{"packageHistory":[{"cve":"CVE-2019-10173","published":"2019-07-23","fixed":"1.4.11","kev":false},{"cve":"CVE-2020-26217","published":"2020-11-16","fixed":"1.4.14-java7","kev":false,"link":{"from":"CVE-2020-26217","to":"CVE-2020-26259","relation":"successor","confidence":"low","kind":"sequence","evidence":[{"kind":"version-step","provenance":"source","package":"Maven:com.thoughtworks.xstream:xstream","fromFixed":"1.4.14-java7","toFixed":"1.4.15","daysApart":30}]}},{"cve":"CVE-2020-26258","published":"2020-12-16","fixed":"1.4.15","kev":false},{"cve":"CVE-2020-26259","published":"2020-12-16","fixed":"1.4.15","kev":false},{"cve":"CVE-2021-21341","published":"2021-03-22","fixed":"1.4.16","kev":false},{"cve":"CVE-2021-21342","published":"2021-03-22","fixed":"1.4.16","kev":false},{"cve":"CVE-2021-21343","published":"2021-03-22","fixed":"1.4.16","kev":false}],"package":"Maven:com.thoughtworks.xstream:xstream"}}