{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-39420 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-39420 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-39420 is a medium-severity vulnerability in 1Panel-dev MaxKB, published on 14 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-39420 and fix it if it is affected.\n\nWhat it is: CVE-2026-39420 is a medium-severity vulnerability in 1Panel-dev MaxKB, published on 14 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-39420 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-2026-39420/ (Markdown: https://insights.sbomify.com/CVE-2026-39420/index.md)","id":"CVE-2026-39420","markdown":"https://insights.sbomify.com/CVE-2026-39420/index.md","name":"CVE-2026-39420","record":{"aliases":["GHSA-7wgv-v2r3-7f7w"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["code_execution","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"AI assistant platform","requires_auth":"low_privilege","summary":"Authenticated users can bypass the LD_PRELOAD sandbox by clearing environment variables, leading to unrestricted remote code execution and network access.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"maxkb","vendor":"maxkb"}],"cvss":{"score":6.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L","version":"3.1"},"cwes":[{"id":"CWE-78","name":"Improper Neutralization of Special Elements used in an OS Command"},{"id":"CWE-693","name":"Protection Mechanism Failure"}],"description":"MaxKB is an open-source AI assistant for enterprise. In versions 2.7.1 and below, an incomplete sandbox protection mechanism allows an authenticated user with tool execution privileges to escape the LD_PRELOAD-based sandbox. By env command the attacker can clear the environment variables and drop the sandbox.so hook, leading to unrestricted Remote Code Execution (RCE) and network access. MaxKB restricts untrusted Python code execution via the Tool Debug API by injecting sandbox.so through the LD_PRELOAD environment variable. This intercepts sensitive C library functions (like execve, socket, open) to restrict network and file access. However, a patch allowed the /usr/bin/env utility to be executed by the sandboxed user. When an attacker is permitted to create subprocesses, they can execute the env -i python command. The -i flag instructs env to completely clear all environment variables before running the target program. This effectively drops the LD_PRELOAD environment variable. The newly spawned Python process will therefore execute natively without any sandbox hooks, bypassing all network and file system restrictions. 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: Sandbox escape via LD_PRELOAD bypass","id":"CVE-2026-39420","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"MaxKB: Sandbox escape via ctypes and unhooked SYS_pkey_mprotect","id":"CVE-2026-39421"},"packages":[],"prev":{"headline":"MaxKB: Sandbox Result Validation Bypass via Tool Output Spoofing","id":"CVE-2026-39419"},"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"}],"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":"Authenticated users can bypass the LD_PRELOAD sandbox by clearing environment variables, leading to unrestricted remote code execution and network access.","url":"https://insights.sbomify.com/CVE-2026-39420/"}