Vulnerability-Lookup

PYSEC-2026-2408

Vulnerability from pysec - Published: 2026-07-13 15:15 - Updated: 2026-07-13 16:03

Details

Summary

The discover_pipeline_files() function in src/ciguard/discovery.py (introduced in v0.8.0 and used by the MCP scan_repo tool shipped in v0.8.1) walks a directory tree following symlinks, with cycle protection via tracking visited resolved paths. An attacker who can plant a symlink in a directory the user (or AI agent) scans can cause discovery to walk into the symlink target and return paths to pipeline-shaped files outside the requested root.

Threat scenario

MCP confused-deputy. A user runs Claude Desktop / Claude Code / Cursor with the ciguard MCP server registered. The agent is fed an adversarial prompt to scan a directory containing planted symlinks (e.g. via a malicious clone or extracted tarball). ciguard.scan_repo walks the symlinks, returning paths and (via subsequent scan calls) file content from ~/.aws/, ~/.config/, /etc/some-pipeline-config/, etc. Pipeline files often contain hardcoded secrets, internal hostnames, deploy keys.

Patch

New follow_symlinks: bool = False parameter on discover_pipeline_files. Default refuses to descend into symlinked directories OR symlinked files.
Belt-and-braces: results are filtered to those whose .resolve() lies under root.resolve(), applied even when callers opt in to follow_symlinks=True.
3 regression tests in tests/test_discovery.py::TestSymlinkSafety.

Discovery

Found during ciguard's first self-conducted penetration test cycle (PTES + OWASP TG v4.2 + CREST framing), 2026-04-26.

CVSS Scoring

CVSS v3.1: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N — 4.4 (Medium)
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N — first.org calc 5.7 (Medium); GitHub's calc returns 2.4 (Low). Vector is correct — calculator profiles differ.

Reproduction

from pathlib import Path
from ciguard.discovery import discover_pipeline_files
# In a victim dir, plant: trojan -> /etc
# (or any other accessible dir containing pipeline-shaped files)
for f in discover_pipeline_files(Path('/tmp/victim')):
    print(f)  # pre-fix: includes paths under /etc; post-fix: only /tmp/victim/

References

Fix released in v0.8.2
CI regression gate added in v0.8.3
https://www.cve.org/CVERecord?id=CVE-2026-44220

See also: GHSA-w828-4qhx-vxx3 — same conceptual pattern (path-validation flaw in an AI-agent tool) in Claude SDK for Python, CWE-59 + CWE-367

Severity

0.0 (None)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N

2.4 (Low)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

Impacted products

Name	purl
ciguard	pkg:pypi/ciguard

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "ciguard",
        "purl": "pkg:pypi/ciguard"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.8.0"
            },
            {
              "fixed": "0.8.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.8.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44220",
    "GHSA-8cxw-cc62-q28v"
  ],
  "details": "## Summary\n\nThe `discover_pipeline_files()` function in `src/ciguard/discovery.py` (introduced in v0.8.0 and used by the MCP `scan_repo` tool shipped in v0.8.1) walks a directory tree following symlinks, with cycle protection via tracking visited resolved paths. An attacker who can plant a symlink in a directory the user (or AI agent) scans can cause discovery to walk into the symlink target and return paths to pipeline-shaped files outside the requested root.\n\n## Threat scenario\n\n**MCP confused-deputy.** A user runs Claude Desktop / Claude Code / Cursor with the ciguard MCP server registered. The agent is fed an adversarial prompt to scan a directory containing planted symlinks (e.g. via a malicious clone or extracted tarball). `ciguard.scan_repo` walks the symlinks, returning paths and (via subsequent `scan` calls) file content from `~/.aws/`, `~/.config/`, `/etc/some-pipeline-config/`, etc. Pipeline files often contain hardcoded secrets, internal hostnames, deploy keys.\n\n## Patch\n\n- New `follow_symlinks: bool = False` parameter on `discover_pipeline_files`. Default refuses to descend into symlinked directories OR symlinked files.\n- Belt-and-braces: results are filtered to those whose `.resolve()` lies under `root.resolve()`, applied even when callers opt in to `follow_symlinks=True`.\n- 3 regression tests in `tests/test_discovery.py::TestSymlinkSafety`.\n\n## Discovery\n\nFound during ciguard\u0027s first self-conducted penetration test cycle (PTES + OWASP TG v4.2 + CREST framing), 2026-04-26.\n\n## CVSS Scoring\n\n- CVSS v3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N` \u2014 4.4 (Medium)\n- CVSS v4.0: `CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N` \u2014 first.org calc 5.7 (Medium); GitHub\u0027s calc returns 2.4 (Low). Vector is correct \u2014 calculator profiles differ.\n\n## Reproduction\n\n```python\nfrom pathlib import Path\nfrom ciguard.discovery import discover_pipeline_files\n# In a victim dir, plant: trojan -\u003e /etc\n# (or any other accessible dir containing pipeline-shaped files)\nfor f in discover_pipeline_files(Path(\u0027/tmp/victim\u0027)):\n    print(f)  # pre-fix: includes paths under /etc; post-fix: only /tmp/victim/\n```\n\n## References\n\n- Fix released in [v0.8.2](https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2)\n- CI regression gate added in [v0.8.3](https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3)\n- https://www.cve.org/CVERecord?id=CVE-2026-44220\n\nSee also: [GHSA-w828-4qhx-vxx3](https://github.com/advisories/GHSA-w828-4qhx-vxx3) \u2014 same conceptual pattern (path-validation flaw in an AI-agent tool) in Claude SDK for Python, CWE-59 + CWE-367",
  "id": "PYSEC-2026-2408",
  "modified": "2026-07-13T16:03:42.013392Z",
  "published": "2026-07-13T15:15:38.557974Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44220"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Jo-Jo98/ciguard"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/ciguard"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-8cxw-cc62-q28v"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "ciguard: discover_pipeline_files follows symlinks out of scan root"
}

CVE-2026-44220 (GCVE-0-2026-44220)

Vulnerability from cvelistv5 – Published: 2026-05-12 19:37 – Updated: 2026-05-13 15:37

Title

ciguard: discover_pipeline_files follows symlinks out of scan root

Summary

ciguard is a static security auditor for CI/CD pipelines. From 0.8.0 to 0.8.1 , the discover_pipeline_files() function in src/ciguard/discovery.py walks a directory tree following symlinks, with cycle protection via tracking visited resolved paths. An attacker who can plant a symlink in a directory the user (or AI agent) scans can cause discovery to walk into the symlink target and return paths to pipeline-shaped files outside the requested root. This vulnerability is fixed in 0.8.2.

Severity

3.2 (Low)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-13 14:58 UTC

CWE

CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Assigner

GitHub_M mitre root

References

1 reference

URL	Tags
https://github.com/Jo-Jo98/ciguard/security/advis…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
Jo-Jo98	ciguard	Affected: >= 0.8.0, < 0.8.2

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-44220",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-13T14:58:20.667032Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-13T15:37:35.696Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "ciguard",
          "vendor": "Jo-Jo98",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.8.0, \u003c 0.8.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "ciguard is a static security auditor for CI/CD pipelines. From 0.8.0 to 0.8.1 , the discover_pipeline_files() function in src/ciguard/discovery.py walks a directory tree following symlinks, with cycle protection via tracking visited resolved paths. An attacker who can plant a symlink in a directory the user (or AI agent) scans can cause discovery to walk into the symlink target and return paths to pipeline-shaped files outside the requested root. This vulnerability is fixed in 0.8.2."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 3.2,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-12T19:37:21.704Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v"
        }
      ],
      "source": {
        "advisory": "GHSA-8cxw-cc62-q28v",
        "discovery": "UNKNOWN"
      },
      "title": "ciguard: discover_pipeline_files follows symlinks out of scan root"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-44220",
    "datePublished": "2026-05-12T19:37:21.704Z",
    "dateReserved": "2026-05-05T15:42:40.517Z",
    "dateUpdated": "2026-05-13T15:37:35.696Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-8CXW-CC62-Q28V

Vulnerability from github – Published: 2026-05-05 22:19 – Updated: 2026-05-15 23:51

Summary

ciguard: discover_pipeline_files follows symlinks out of scan root

Details

Summary

Threat scenario

Patch

New follow_symlinks: bool = False parameter on discover_pipeline_files. Default refuses to descend into symlinked directories OR symlinked files.
Belt-and-braces: results are filtered to those whose .resolve() lies under root.resolve(), applied even when callers opt in to follow_symlinks=True.
3 regression tests in tests/test_discovery.py::TestSymlinkSafety.

Discovery

Found during ciguard's first self-conducted penetration test cycle (PTES + OWASP TG v4.2 + CREST framing), 2026-04-26.

CVSS Scoring

CVSS v3.1: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N — 4.4 (Medium)
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N — first.org calc 5.7 (Medium); GitHub's calc returns 2.4 (Low). Vector is correct — calculator profiles differ.

Reproduction

from pathlib import Path
from ciguard.discovery import discover_pipeline_files
# In a victim dir, plant: trojan -> /etc
# (or any other accessible dir containing pipeline-shaped files)
for f in discover_pipeline_files(Path('/tmp/victim')):
    print(f)  # pre-fix: includes paths under /etc; post-fix: only /tmp/victim/

References

Fix released in v0.8.2
CI regression gate added in v0.8.3
https://www.cve.org/CVERecord?id=CVE-2026-44220

See also: GHSA-w828-4qhx-vxx3 — same conceptual pattern (path-validation flaw in an AI-agent tool) in Claude SDK for Python, CWE-59 + CWE-367

Severity

0.0 (None)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N

2.4 (Low)


                  
                    CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.8.1"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "ciguard"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.8.0"
            },
            {
              "fixed": "0.8.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44220"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-59"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-05T22:19:23Z",
    "nvd_published_at": "2026-05-12T20:16:42Z",
    "severity": "LOW"
  },
  "details": "## Summary\n\nThe `discover_pipeline_files()` function in `src/ciguard/discovery.py` (introduced in v0.8.0 and used by the MCP `scan_repo` tool shipped in v0.8.1) walks a directory tree following symlinks, with cycle protection via tracking visited resolved paths. An attacker who can plant a symlink in a directory the user (or AI agent) scans can cause discovery to walk into the symlink target and return paths to pipeline-shaped files outside the requested root.\n\n## Threat scenario\n\n**MCP confused-deputy.** A user runs Claude Desktop / Claude Code / Cursor with the ciguard MCP server registered. The agent is fed an adversarial prompt to scan a directory containing planted symlinks (e.g. via a malicious clone or extracted tarball). `ciguard.scan_repo` walks the symlinks, returning paths and (via subsequent `scan` calls) file content from `~/.aws/`, `~/.config/`, `/etc/some-pipeline-config/`, etc. Pipeline files often contain hardcoded secrets, internal hostnames, deploy keys.\n\n## Patch\n\n- New `follow_symlinks: bool = False` parameter on `discover_pipeline_files`. Default refuses to descend into symlinked directories OR symlinked files.\n- Belt-and-braces: results are filtered to those whose `.resolve()` lies under `root.resolve()`, applied even when callers opt in to `follow_symlinks=True`.\n- 3 regression tests in `tests/test_discovery.py::TestSymlinkSafety`.\n\n## Discovery\n\nFound during ciguard\u0027s first self-conducted penetration test cycle (PTES + OWASP TG v4.2 + CREST framing), 2026-04-26.\n\n## CVSS Scoring\n\n- CVSS v3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N` \u2014 4.4 (Medium)\n- CVSS v4.0: `CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N` \u2014 first.org calc 5.7 (Medium); GitHub\u0027s calc returns 2.4 (Low). Vector is correct \u2014 calculator profiles differ.\n\n## Reproduction\n\n```python\nfrom pathlib import Path\nfrom ciguard.discovery import discover_pipeline_files\n# In a victim dir, plant: trojan -\u003e /etc\n# (or any other accessible dir containing pipeline-shaped files)\nfor f in discover_pipeline_files(Path(\u0027/tmp/victim\u0027)):\n    print(f)  # pre-fix: includes paths under /etc; post-fix: only /tmp/victim/\n```\n\n## References\n\n- Fix released in [v0.8.2](https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2)\n- CI regression gate added in [v0.8.3](https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3)\n- https://www.cve.org/CVERecord?id=CVE-2026-44220\n\nSee also: [GHSA-w828-4qhx-vxx3](https://github.com/advisories/GHSA-w828-4qhx-vxx3) \u2014 same conceptual pattern (path-validation flaw in an AI-agent tool) in Claude SDK for Python, CWE-59 + CWE-367",
  "id": "GHSA-8cxw-cc62-q28v",
  "modified": "2026-05-15T23:51:39Z",
  "published": "2026-05-05T22:19:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44220"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Jo-Jo98/ciguard"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "ciguard: discover_pipeline_files follows symlinks out of scan root"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

PYSEC-2026-2408

Summary

Threat scenario

Patch

Discovery

CVSS Scoring

Reproduction

References

CVE-2026-44220 (GCVE-0-2026-44220)

GHSA-8CXW-CC62-Q28V

Summary

Threat scenario

Patch

Discovery

CVSS Scoring

Reproduction

References

Tags

Sightings

Nomenclature

Related by attack behaviour