CVE-2026-53753

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Source

https://cve.org/CVERecord?id=CVE-2026-53753

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53753.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-53753

Aliases

Published

2026-06-23T18:17:18Z

Modified

2026-08-12T03:51:30Z

Severity

9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator

Summary

Crawl4AI: AST Sandbox Escape via gi_frame.f_back Chain - Pre-Auth RCE in Docker API

Details

Crawl4AI is an open-source LLM friendly web crawler & scraper. Prior to 0.8.7, the _safe_eval_expression() function in the computed fields feature uses an AST validator that only blocks attributes starting with underscore. Python generator and frame object attributes (gi_frame, f_back, f_builtins) do NOT start with underscore, enabling a complete sandbox escape to achieve arbitrary code execution. The attack requires no authentication (JWT disabled by default) and is triggered via POST /crawl with a crafted extraction schema. This vulnerability is fixed in 0.8.7.

Database specific

{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-913",
        "CWE-94"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53753.json"
}

References

Affected packages

Git / github.com/unclecode/crawl4ai

Affected ranges

Type

GIT

Repo

https://github.com/unclecode/crawl4ai

Events

Introduced

Fixed

7b280d36b150b544bf0994285b4755dca18c2149

Database specific

Show details

{
    "cpe": "cpe:2.3:a:kidocode:crawl4ai:*:*:*:*:*:*:*:*",
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.8.7"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE"
    ]
}

Affected versions

0.*

0.3.4

docker-rebuild-v0.*

docker-rebuild-v0.8.6

v.*

v.3.72

v0.*

v0.0.75

v0.1.0

v0.2.0

v0.2.1

v0.2.4

v0.2.6

v0.2.7

v0.2.71

v0.2.72

v0.2.73

v0.2.74

v0.2.77

v0.3.0

v0.3.3

v0.3.6

v0.3.745

v0.4.24

v0.4.243

v0.5.0.post1

v0.6.3

v0.7.0

v0.7.1

v0.7.2

v0.7.3

v0.7.4

v0.8.6

vr0.*

vr0.6.0

vr0.6.0rc1

vr0.6.3

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53753.json"