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🐍 PyPI
Not in CISA KEV
LOW severity

CVE-2026-44220 — ciguard

LOW

CVE-2026-44220 is a low-severity (CVSS 3.2) CWE-59 vulnerability in ciguard. A fix is available for ciguard — see the affected versions and patch details below.

ciguard: discover_pipeline_files follows symlinks out of scan root

Also known asGHSA-8cxw-cc62-q28vPYSEC-2026-2408
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44220.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs12th percentile — riskier than 12% of all scored CVEsHighest risk
0.00%0.24%0.48%0.71%0.0%0.2%Jun 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
🐍ciguard

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

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

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

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIciguard≥ 0.8.0&&< 0.8.20.8.2pip install --upgrade 'ciguard==0.8.2'

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ciguard, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update ciguard to 0.8.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44220 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

## 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.
O3 Security · Impact-Aware SCA

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CVE-2026-44220: ciguard — Fixed in 0.8.2