{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-21393 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-21393 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-21393 is a medium-severity cross-site scripting vulnerability in Six Apart Ltd. Movable Type (Cloud Edition), published on 4 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-21393 and fix it if it is affected.\n\nWhat it is: CVE-2026-21393 is a medium-severity cross-site scripting vulnerability in Six Apart Ltd. Movable Type (Cloud Edition), published on 4 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-21393 in the wild and no public exploit code.\n\nAffected product: Six Apart Ltd. Movable Type (Cloud Edition). No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2026-21393/ (Markdown: https://insights.sbomify.com/CVE-2026-21393/index.md)","id":"CVE-2026-21393","markdown":"https://insights.sbomify.com/CVE-2026-21393/index.md","name":"CVE-2026-21393","record":{"aliases":["GHSA-343f-q34x-rjhr"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["code_execution","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"Movable Type CMS","requires_auth":"low_privilege","summary":"Attackers can inject malicious scripts via comments, leading to arbitrary code execution in logged-in users' browsers.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"jpcert","cpe":[],"cvss":{"score":4.8,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"Movable Type contains a stored cross-site scripting vulnerability in Edit Comment. If crafted input is stored by an attacker, arbitrary script may be executed on a logged-in user's web browser. Note that Movable Type 7 series and 8.4 series, which are End-of-Life (EOL), are affected by the vulnerability as well.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Cross-site scripting in Movable Type (Cloud Edition)","id":"CVE-2026-21393","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"Memory corruption in Intel(R) Open Volume Kernel Library (Intel(R) Open VKL) library maintained by intel(R)","id":"CVE-2026-21399"},"packages":[],"prev":{"headline":"Improper Claim Validation in PingAM OIDC Provider","id":"CVE-2026-21391"},"products":["Movable Type (Cloud Edition)","Movable Type (Software Edition)","Movable Type Advanced (Software Edition)","Movable Type Premium (Advanced Edition) (Software Edition)","Movable Type Premium (Cloud Edition)","Movable Type Premium (Software Edition)"],"published":"2026-02-04","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-02-04","vendors":["Six Apart Ltd."]},"summary":"Attackers can inject malicious scripts via comments, leading to arbitrary code execution in logged-in users' browsers.","url":"https://insights.sbomify.com/CVE-2026-21393/"}