Security Vulnerability Report
中文
CVE-2026-40701 CVSS 4.8 MEDIUM

CVE-2026-40701

Published: 2026-05-13 16:16:44
Last Modified: 2026-05-13 16:27:11

Description

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_module module when the ssl_verify_client directive is set to "on" or "optional," and the ssl_ocsp directive is set to "on" or the leaf parameters are configured with a resolver. With this configuration, an unauthenticated attacker can send requests along with conditions beyond its control that may cause a heap-use-after-free error in the NGINX worker process. This vulnerability may result in limited modification of data or the NGINX worker process restarting.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS Details

CVSS Score
4.8
Severity
MEDIUM
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Configurations (Affected Products)

No configuration data available.

NGINX Plus (具体版本请参考官方公告)
NGINX Open Source (具体版本请参考官方公告)

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
import socket import ssl # This script attempts to connect to a target to verify the SSL configuration. # It simulates the conditions required for CVE-2026-40701. # Note: This is a connection test, not an exploit. def check_vulnerability(host, port): context = ssl.create_default_context() # Load client certificate if required by server (ssl_verify_client) # context.load_cert_chain(certfile="client.pem", keyfile="client.key") try: with socket.create_connection((host, port)) as sock: with context.wrap_socket(sock, server_hostname=host) as ssock: print(f"Connected to {host} on port {port}") print(f"Protocol: {ssock.version()}") # Send a basic HTTP request to trigger OCSP stapling logic ssock.sendall(b"GET / HTTP/1.1\r\nHost: " + host.encode() + b"\r\n\r\n") response = ssock.recv(4096) print(response.decode()) except Exception as e: print(f"Error: {e}") if __name__ == "__main__": TARGET_HOST = "example.com" TARGET_PORT = 443 check_vulnerability(TARGET_HOST, TARGET_PORT)

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-40701", "sourceIdentifier": "[email protected]", "published": "2026-05-13T16:16:43.863", "lastModified": "2026-05-13T16:27:11.127", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_module module when the ssl_verify_client directive is set to \"on\" or \"optional,\" and the ssl_ocsp directive is set to \"on\" or the leaf parameters are configured with a resolver. With this configuration, an unauthenticated attacker can send requests along with conditions beyond its control that may cause a heap-use-after-free error in the NGINX worker process. This vulnerability may result in limited modification of data or the NGINX worker process restarting.\n\n\n\n Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L", "baseScore": 4.8, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.2, "impactScore": 2.5}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-416"}]}], "references": [{"url": "https://my.f5.com/manage/s/article/K000161021", "source": "[email protected]"}]}}