{"answers":{"affected":"2 open source packages ship an affected version, including com.thoughtworks.xstream:xstream. It affects 4 products.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-26258 exists.","fix":"Upgrade com.thoughtworks.xstream:xstream to 1.4.15 or later.","what":"CVE-2020-26258 is a medium-severity server-side request forgery vulnerability in Apache Struts, published on 16 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2020-26258 and fix it if it is affected.\n\nWhat it is: CVE-2020-26258 is a medium-severity server-side request forgery vulnerability in Apache Struts, published on 16 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-26258 exists.\n\nAffected packages and fixed versions:\n- com.thoughtworks.xstream:xstream (Maven): affected all versions; fixed in 1.4.15\n- com.thoughtworks.xstream:xstream (Maven): affected all versions; fixed in 1.4.15\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2020-26258/ (Markdown: https://insights.sbomify.com/CVE-2020-26258/index.md)","id":"CVE-2020-26258","markdown":"https://insights.sbomify.com/CVE-2020-26258/index.md","name":"CVE-2020-26258","record":{"aliases":["DEBIAN-CVE-2020-26258","GHSA-4cch-wxpw-8p28","UBUNTU-CVE-2020-26258"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read"],"network_reachable":"yes","non_default_config":true,"product_category":"Java XML serialization library","requires_auth":"low_privilege","summary":"Remote attackers can trigger Server-Side Request Forgery in XStream when unmarshalling XML if using the default blacklist configuration.","user_interaction":"not_required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"struts","vendor":"apache"},{"product":"debian_linux","vendor":"debian"},{"product":"fedora","vendor":"fedoraproject"},{"product":"xstream","vendor":"xstream"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-918","name":"Server-Side Request Forgery"}],"description":"XStream is a Java library to serialize objects to XML and back again. In XStream before version 1.4.15, a Server-Side Forgery Request vulnerability can be activated when unmarshalling. The vulnerability may allow a remote attacker to request data from internal resources that are not publicly available 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 if 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.","ecosystems":["Maven"],"exploits":{"exploitdb":0,"first_seen":"2021-01-22","github_poc":2,"max_poc_stars":0,"metasploit":0,"nuclei":1,"refs":[{"date":"2021-01-22T08:44:24Z","kind":"github_poc","ref":"https://github.com/Al1ex/CVE-2020-26258","stars":0,"title":"CVE-2020-26258 \u0026\u0026 XStream SSRF"},{"date":"2025-07-11T03:53:10Z","kind":"github_poc","ref":"https://github.com/cuijiung/xstream-CVE-2020-26258","stars":0,"title":null},{"date":null,"kind":"nuclei","ref":"http/cves/2020/CVE-2020-26258.yaml","stars":null,"title":"XStream \u003c1.4.15 - Server-Side Request Forgery"}],"tier":"weaponised"},"has_fix":true,"headline":"Server-Side Forgery Request can be activated unmarshalling with XStream","id":"CVE-2020-26258","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Maven","product":"apache:struts","products":["apache:struts","debian:debian_linux","fedoraproject:fedora"],"type":"ssrf","year":"2020"},"n_packages":2,"n_references":9,"next":{"headline":"XStream is vulnerable to an Arbitrary File Deletion on the local host when unmarshalling","id":"CVE-2020-26259"},"packages":[{"ecosystem":"Maven","fixed":["1.4.15"],"introduced":["0"],"last_affected":[],"package":"com.thoughtworks.xstream:xstream","purl":null,"source":"GHSA-4cch-wxpw-8p28"},{"ecosystem":"Maven","fixed":["1.4.15"],"introduced":["0"],"last_affected":[],"package":"com.thoughtworks.xstream:xstream","purl":"pkg:maven/com.thoughtworks.xstream/xstream","source":"GHSA-4cch-wxpw-8p28"}],"prev":{"headline":"Denial of service attack via incorrect parameters to federation APIs","id":"CVE-2020-26257"},"products":["xstream"],"published":"2020-12-16","related":[{"cvss_score":9.8,"headline":"Apache Struts Remote Code Execution","id":"CVE-2020-17530","kev_date_added":"2021-11-03","published":"2020-12-11"},{"cvss_score":9.8,"headline":"Apache Struts 1 Improper Input Validation","id":"CVE-2017-9791","kev_date_added":"2022-02-10","published":"2017-07-10"},{"cvss_score":9.8,"headline":"Apache Struts Remote Code Execution","id":"CVE-2017-5638","kev_date_added":"2021-11-03","published":"2017-03-11"},{"cvss_score":9.8,"headline":"Apache Struts 2 Improper Input Validation","id":"CVE-2012-0391","kev_date_added":"2022-01-21","published":"2012-01-08"},{"cvss_score":8.1,"headline":"Apache Struts Remote Code Execution","id":"CVE-2018-11776","kev_date_added":"2021-11-03","published":"2018-08-22"},{"cvss_score":8.1,"headline":"Apache Struts Deserialization of Untrusted Data","id":"CVE-2017-9805","kev_date_added":"2021-11-03","published":"2017-09-15"},{"cvss_score":8.1,"headline":"Apache Struts Command Injection","id":"CVE-2016-3081","kev_date_added":"2026-10-08","published":"2016-04-26"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"attribution","licence":"MIT","name":"Nuclei templates"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-07","vendors":["x-stream"]},"summary":"Remote attackers can trigger Server-Side Request Forgery in XStream when unmarshalling XML if using the default blacklist configuration.","url":"https://insights.sbomify.com/CVE-2020-26258/"}