Cyber Posture

CVE-2026-27815

Critical

Published: 26 March 2026

Published
26 March 2026
Modified
31 March 2026
KEV Added
Patch
CVSS Score 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0004 13.7th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-27815 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Linuxfoundation Everest. Its CVSS base score is 9.1 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 2 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Requires validation of incoming MQTT payloads, including bounds checking on variable-length payment_options lists, to prevent out-of-bounds writes.

prevent

Implements memory protections like stack guards and address randomization to block exploitation of out-of-bounds writes corrupting EVSE state.

prevent

Mandates timely flaw remediation by applying the patch in EVerest version 2026.02.0 to eliminate the buffer overflow vulnerability.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

OOB write in network-exposed EV charging component (MQTT/ISO15118 handler) directly enables remote unauthenticated exploitation of a public-facing or remote service, resulting in process crash or state corruption that maps to application exploitation for DoS.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD 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…

more

out-of-bounds writes and corrupt adjacent EVSE state or crash the process. Version 2026.02.0 contains a patch.

Deeper analysisAI

CVE-2026-27815 is a high-severity out-of-bounds write vulnerability (CWE-787) in the EVerest EV charging software stack, affecting versions prior to 2026.02.0. The issue resides in the ISO15118_chargerImpl::handle_session_setup function, which copies a variable-length payment_options list into a fixed-size array of length 2 without performing bounds checking. Schema validation is disabled by default, enabling oversized MQTT command payloads to trigger the out-of-bounds write, which can corrupt adjacent EVSE state or crash the process. The vulnerability carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H).

Remote attackers with network access can exploit this vulnerability without authentication, privileges, or user interaction due to its low attack complexity. By sending crafted oversized MQTT payloads to the affected component, attackers can achieve integrity and availability impacts, including corruption of nearby memory structures in the EVSE state or denial of service via process crashes. There is no confidentiality impact.

The GitHub Security Advisory (GHSA-7wmg-crc8-6xxf) confirms that EVerest version 2026.02.0 addresses the issue with a patch. Security practitioners should upgrade to this version or later and consider enabling schema validation where feasible to mitigate exploitation risks.

Details

CWE(s)

Affected Products

linuxfoundation
everest
≤ 2026.02.0

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References