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.
PUBLISHED5.2CWE-59
ciguard: discover_pipeline_files follows symlinks out of scan root
Problem type
Affected products
Jo-Jo98
ciguard
>= 0.8.0, < 0.8.2 - AFFECTED
References
GitHub Security Advisories
GHSA-8cxw-cc62-q28v
ciguard: discover_pipeline_files follows symlinks out of scan root
https://github.com/advisories/GHSA-8cxw-cc62-q28vSummary
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 = Falseparameter ondiscover_pipeline_files. Default refuses to descend into symlinked directories OR symlinked files. - Belt-and-braces: results are filtered to those whose
.resolve()lies underroot.resolve(), applied even when callers opt in tofollow_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
github.com
https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v
github.com
https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.2
github.com
https://github.com/Jo-Jo98/ciguard/releases/tag/v0.8.3
nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2026-44220
github.com
https://github.com/advisories/GHSA-8cxw-cc62-q28v
JSON source
https://cveawg.mitre.org/api/cve/CVE-2026-44220Click to expand
{
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"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-44220",
"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"assignerShortName": "GitHub_M",
"dateUpdated": "2026-05-12T19:37:21.704Z",
"dateReserved": "2026-05-05T15:42:40.517Z",
"datePublished": "2026-05-12T19:37:21.704Z",
"state": "PUBLISHED"
},
"containers": {
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},
"title": "ciguard: discover_pipeline_files follows symlinks out of scan root",
"descriptions": [
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"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."
}
],
"affected": [
{
"vendor": "Jo-Jo98",
"product": "ciguard",
"versions": [
{
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"status": "affected"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "CWE-59: Improper Link Resolution Before File Access ('Link Following')",
"cweId": "CWE-59",
"type": "CWE"
}
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"references": [
{
"url": "https://github.com/Jo-Jo98/ciguard/security/advisories/GHSA-8cxw-cc62-q28v",
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"metrics": [
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"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "REQUIRED",
"scope": "CHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"availabilityImpact": "NONE",
"baseScore": 3.2,
"baseSeverity": "LOW"
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}
}