{"id":"CVE-2026-61536","summary":"Banks: Unsafe importlib.import_module of attacker-controlled Tool.import_path in CompletionExtension allows RCE","details":"Banks generates meaningful LLM prompts using a simple template language. In versions prior to 2.4.3, banks parses Tool JSON objects from the rendered body of {% completion %} blocks and later resolves their import_path field through importlib.import_module(...) + getattr(...) to obtain the callable that handles a tool call. There is no allowlist or sanitization on import_path, so any importable Python attribute (e.g. os.system, subprocess.getoutput) can be selected. When the LLM emits a tool_calls entry whose function.name matches the attacker-supplied tool name, the resolved callable is invoked with kwargs decoded from tool_call.function.arguments, yielding arbitrary code execution in the banks-hosting process. This is distinct from GHSA-gphh-9q3h-jgpp / CVE-2026-44209. That advisory was fixed in 2.4.2 by switching src/banks/env.py from Environment to SandboxedEnvironment. The fix does not touch src/banks/extensions/completion.py, and the unsafe import + getattr chain still executes on 2.4.2. The malicious Tool JSON is plain text in the rendered template body — it requires no Jinja attribute access, so the sandbox is irrelevant. This issue has been fixed in version 2.4.3.","aliases":["GHSA-64vx-6h2c-rjh7"],"modified":"2026-08-02T03:32:14.778277727Z","published":"2026-07-30T16:50:01.730Z","database_specific":{"cwe_ids":["CWE-470","CWE-94"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61536.json","cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61536.json"},{"type":"ADVISORY","url":"https://github.com/masci/banks/security/advisories/GHSA-64vx-6h2c-rjh7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61536"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/masci/banks","events":[{"introduced":"0"},{"fixed":"1ef6c873927bb9664da69e3f024b6e4e6bf60ac5"}],"database_specific":{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"0"},{"fixed":"2.4.3"}]}}],"versions":["v2.4.2","v2.4.1","v2.4.0","v2.3.0","v2.2.0","v2.1.3","v2.1.2","v2.1.1","v2.1.0","v2.0.0","v1.8.0","v1.7.1","v1.7.0","v1.6.1","v1.6.0","v1.5.0","v1.4.0","v1.3.0","v1.2.1","v1.2.0","v1.1.0","v1.0.0","v0.6.0","v0.5.0","v0.4.1","v0.4.0","v0.3.1","v0.3.0","v0.2.0","v0.1.1","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61536.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}