GHSA-4qqr-vv2q-cmr5

Suggest an improvement
Source
https://github.com/advisories/GHSA-4qqr-vv2q-cmr5
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-4qqr-vv2q-cmr5/GHSA-4qqr-vv2q-cmr5.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-4qqr-vv2q-cmr5
Aliases
Published
2026-06-16T21:00:04Z
Modified
2026-07-20T21:30:31Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
Summary
Crawl4AI: SSRF filter bypass in Docker server via IPv6 transition forms (NAT64 / 6to4 / unspecified / v4-mapped)
Details

Summary

The Docker API server's SSRF protection (validate_webhook_url / validate_url_destination in deploy/docker/utils.py) used an explicit IPv4/IPv6 CIDR blocklist that missed several address families. An attacker could reach internal services and cloud metadata endpoints (e.g. 169.254.169.254) despite the filter by encoding an internal IPv4 address inside an IPv6 transition form, or by using the IPv6 unspecified address.

Because the Docker API is unauthenticated by default (jwt_enabled: false), no credentials are required.

Affected paths

The blocklist was applied to crawl URLs (POST /crawl, /md, /html, /screenshot, /pdf, /execute_js) and webhook URLs (/crawl/job, /llm/job). All shared the same incomplete check.

Bypasses

The following all resolve to (or route to) blocked internal addresses but were NOT caught:

  • IPv6 unspecified ::
  • NAT64 64:ff9b::a9fe:a9fe (embeds 169.254.169.254)
  • 6to4 2002:a9fe:a9fe:: (embeds 169.254.169.254)
  • IPv4-mapped ::ffff:169.254.169.254
  • IPv4-compatible ::a9fe:a9fe

The error message also echoed the resolved internal IP, acting as a minor DNS/oracle leak.

Impact

Server-Side Request Forgery: an unauthenticated attacker can make the server fetch internal-network URLs and cloud instance-metadata endpoints, potentially exposing internal services and cloud credentials.

Fix

The blocklist is replaced by a single rule: reject any resolved IP where not ip.is_global, evaluated on the address AND every embedded IPv4 transition form (v4-mapped, NAT64 64:ff9b::/96, 6to4 2002::/16, v4-compat ::/96). Error messages are now opaque and no longer echo the resolved IP.

Workarounds

  • Upgrade to the patched version.
  • Enable authentication (CRAWL4AI_API_TOKEN).
  • Restrict the container's outbound network access (egress firewall / no metadata route).

Credits

Internal security audit (Crawl4AI maintainers).

Database specific 
{
    "cwe_ids":  [
        "CWE-918"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-06-16T21:00:04Z",
    "nvd_published_at":  "2026-06-23T19:17:07Z",
    "severity":  "HIGH"
}
References

Affected packages

PyPI / crawl4ai

Package

Name
crawl4ai
View open source insights on deps.dev
Purl
pkg:pypi/crawl4ai

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.8.8

Affected versions

0.*
0.3.0
0.3.1
0.3.2
0.3.3
0.3.4
0.3.5
0.3.6
0.3.7
0.3.8
0.3.71
0.3.72
0.3.73
0.3.74
0.3.731
0.3.741
0.3.742
0.3.743
0.3.744
0.3.745
0.3.746
0.4.0
0.4.1
0.4.3b1
0.4.3b2
0.4.3b3
0.4.21
0.4.22
0.4.23
0.4.24
0.4.241
0.4.242
0.4.243
0.4.244
0.4.245
0.4.246
0.4.247
0.4.248b3
0.4.248
0.5.0
0.5.0.post1
0.5.0.post2
0.5.0.post3
0.5.0.post4
0.5.0.post5
0.5.0.post6
0.5.0.post7
0.5.0.post8
0.6.0rc1
0.6.0
0.6.1
0.6.2
0.6.3
0.7.0
0.7.1
0.7.2
0.7.3
0.7.4
0.7.5
0.7.6
0.7.7
0.7.8
0.8.0
0.8.5
0.8.6
0.8.7

Database specific

last_known_affected_version_range 
"<= 0.8.7"
source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-4qqr-vv2q-cmr5/GHSA-4qqr-vv2q-cmr5.json"