CVE-2026-42952: Charging Station Backend DoS Vulnerability

CVE-2026-42952 Overview

CVE-2026-42952 is a high-severity vulnerability affecting a charging station backend that lacks throttling on repeated authentication attempts. An unauthenticated remote attacker can flood the authentication interface with requests, exhausting backend resources and producing a denial-of-service condition. The weakness maps to [CWE-307: Improper Restriction of Excessive Authentication Attempts]. CISA published the issue in ICS Advisory ICSA-26-188-01, indicating operational technology (OT) exposure. The vulnerability is reachable over the network with low attack complexity and requires no privileges or user interaction.

Critical Impact
Unthrottled authentication requests permit remote attackers to disrupt charging station backend availability and integrity without credentials.

Affected Products

Charging station backend referenced in CISA ICS Advisory ICSA-26-188-01
Specific vendor and product identifiers were not enumerated in the NVD record
Refer to the CSAF JSON advisory file for product metadata

Discovery Timeline

2026-07-10 - CVE-2026-42952 published to the National Vulnerability Database
2026-07-14 - Last updated in NVD database

Technical Details for CVE-2026-42952

Vulnerability Analysis

The charging station backend accepts authentication attempts without applying rate limiting, lockout thresholds, or exponential backoff. An attacker can submit high volumes of authentication requests from one or more sources. Each request consumes backend compute, memory, and connection state on the authentication service. Sustained request volume degrades service responsiveness and can render the backend unavailable to legitimate charging sessions.

The CVSS v4.0 vector indicates network reachability and impact on integrity of the vulnerable system. Because charging station backends often coordinate session authorization, billing, and grid interaction, availability loss can cascade into operational disruption across connected charging assets. The Exploit Prediction Scoring System places the near-term exploitation probability at 0.38%.

Root Cause

The root cause is missing enforcement of authentication attempt limits, categorized under CWE-307. The backend does not track failed attempts per identity or source, does not impose delays between attempts, and does not throttle concurrent authentication sessions. Without these controls, the authentication endpoint behaves as an unbounded resource consumer.

Attack Vector

An attacker sends repeated authentication requests over the network to the charging station backend authentication interface. No credentials or user interaction are required. The attacker can automate the attack using standard HTTP or protocol-specific clients targeting the exposed authentication endpoint. Distributed sources amplify the impact and evade single-IP mitigations.

No verified public proof-of-concept code is available for CVE-2026-42952. Consult the CISA advisory for coordinated technical details.

Detection Methods for CVE-2026-42952

Indicators of Compromise

High volumes of authentication requests to the charging station backend from single or distributed sources within short time windows
Elevated authentication failure counts without corresponding successful sessions
Backend service latency spikes, connection pool saturation, or process restarts coinciding with authentication traffic bursts
Unusual client User-Agent strings or protocol clients targeting the authentication endpoint

Detection Strategies

Baseline normal authentication request rates per source, then alert on statistical deviations
Correlate authentication failure counts with backend CPU, memory, and connection metrics to identify resource exhaustion patterns
Inspect network flow records for repeated short-lived connections to the authentication service port

Monitoring Recommendations

Enable verbose authentication logging on the charging station backend and forward events to a centralized SIEM
Monitor OT segment egress and ingress for anomalous traffic to charging infrastructure
Track service-level indicators such as authentication response time and error rate with alerting thresholds
Review CISA ICS advisory feeds and vendor bulletins for updated indicators tied to ICSA-26-188-01

How to Mitigate CVE-2026-42952

Immediate Actions Required

Apply vendor-supplied updates referenced in CISA ICS Advisory ICSA-26-188-01 as soon as they are available for your deployment
Restrict network access to the authentication endpoint to trusted management networks and known charging station clients
Deploy rate limiting at a reverse proxy, API gateway, or firewall in front of the backend authentication interface
Review authentication logs for prior high-volume attempts that may indicate reconnaissance or exploitation

Patch Information

Refer to the vendor guidance and remediation instructions in the CISA ICS Advisory ICSA-26-188-01 and the corresponding CSAF JSON advisory. Contact information for coordinated response is available via Hydro-Quebec.

Workarounds

Enforce network-layer rate limits and connection quotas on traffic to the authentication endpoint
Place the backend behind a Web Application Firewall (WAF) or API gateway that implements per-source throttling and CAPTCHA challenges where feasible
Segment charging infrastructure into isolated network zones and require VPN or mutual TLS for management access
Configure monitoring to automatically block source addresses exceeding defined authentication attempt thresholds

bash

# Example: nftables rate limit for authentication endpoint (adjust interface, port, and thresholds)
nft add table inet cs_backend
nft add chain inet cs_backend input { type filter hook input priority 0 \; }
nft add rule inet cs_backend input tcp dport 443 \
  ct state new limit rate 10/second burst 20 packets accept
nft add rule inet cs_backend input tcp dport 443 ct state new drop