{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-39426 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-39426 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-39426 is a medium-severity cross-site scripting vulnerability in 1Panel-dev MaxKB, published on 14 Apr 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-2026-39426 and fix it if it is affected.\n\nWhat it is: CVE-2026-39426 is a medium-severity cross-site scripting vulnerability in 1Panel-dev MaxKB, published on 14 Apr 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-2026-39426 in the wild and no public exploit code.\n\nAffected product: 1Panel-dev MaxKB. 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-2026-39426/ (Markdown: https://insights.sbomify.com/CVE-2026-39426/index.md)","id":"CVE-2026-39426","markdown":"https://insights.sbomify.com/CVE-2026-39426/index.md","name":"CVE-2026-39426","record":{"aliases":["GHSA-q2qg-43vq-f2wv"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["account_takeover","data_read"],"network_reachable":"yes","non_default_config":false,"product_category":"AI assistant platform","requires_auth":"low_privilege","summary":"Attackers can inject malicious scripts via unsanitized iframe tags in AI responses, leading to session hijacking and data exposure for users.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"maxkb","vendor":"maxkb"}],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/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":"MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain a Stored Cross-Site Scripting (XSS) vulnerability where the frontend's MdRenderer.vue component parses custom \u003ciframe_render\u003e tags from LLM responses or Application Prologue configurations, bypassing standard Markdown sanitization and XSS filtering. The unsanitized HTML content is passed to the IframeRender.vue component, which renders it directly into an \u003ciframe\u003e via the srcdoc attribute configured with sandbox=\"allow-scripts allow-same-origin\". This can be a dangerous combination, allowing injected scripts to escape the iframe and execute JavaScript in the parent window using window.parent. Since the Prologue is rendered for any user visiting an application's chat interface, this results in a high-impact Stored XSS that can lead to session hijacking, unauthorized actions, and sensitive data exposure. This issue has been fixed in version 2.8.0.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"MaxKB: Stored XSS via Unsanitized iframe_render Parsing","id":"CVE-2026-39426","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"xss","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"CubeCart: Stored Cross-Site Scripting (XSS)","id":"CVE-2026-39428"},"packages":[],"prev":{"headline":"MaxKB: Stored XSS via Unsanitized html_rander Tags in Markdown Rendering","id":"CVE-2026-39425"},"products":["MaxKB"],"published":"2026-04-14","related":[{"cvss_score":8.8,"headline":"MaxKB vulnerable to privilege escalation through sandbox bypass","id":"CVE-2025-66419","kev_date_added":null,"published":"2025-12-11"},{"cvss_score":8.8,"headline":"MaxKB has a Python sandbox LD_PRELOAD bypass","id":"CVE-2025-66446","kev_date_added":null,"published":"2025-12-11"},{"cvss_score":7.4,"headline":"MaxKB has SSRF in sandbox","id":"CVE-2025-64511","kev_date_added":null,"published":"2025-11-13"},{"cvss_score":6.9,"headline":"MaxKB has Stored XSS via ChatHeadersMiddleware","id":"CVE-2026-39422","kev_date_added":null,"published":"2026-04-14"},{"cvss_score":6.9,"headline":"Stored XSS via Eval Injection in EchartsRander Component","id":"CVE-2026-39423","kev_date_added":null,"published":"2026-04-14"},{"cvss_score":6.8,"headline":"MaxKB RCE vulnerability in function library","id":"CVE-2024-56137","kev_date_added":null,"published":"2025-01-02"},{"cvss_score":6.3,"headline":"MaxKB: Sandbox escape via LD_PRELOAD bypass","id":"CVE-2026-39420","kev_date_added":null,"published":"2026-04-14"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-04-16","vendors":["1Panel-dev"]},"summary":"Attackers can inject malicious scripts via unsanitized iframe tags in AI responses, leading to session hijacking and data exposure for users.","url":"https://insights.sbomify.com/CVE-2026-39426/"}