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

2026-06-23T18:17:18.936Z

Modified

2026-07-08T08:12:35.268971550Z

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 safeevalexpression() function in the computed fields feature uses an AST validator that only blocks attributes starting with underscore. Python generator and frame object attributes (giframe, fback, fbuiltins) 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

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

References

Affected packages

Git / github.com/unclecode/crawl4ai

Affected ranges

Type

GIT

Repo

https://github.com/unclecode/crawl4ai

Events

Introduced

Fixed

7b280d36b150b544bf0994285b4755dca18c2149

Database specific

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

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"