CVE-2026-54479: Predictable Session Identifiers in WebSocket Charging Station Backend

Technical summary

The vulnerability exists in how the WebSocket backend generates and validates session identifiers tied to charging station identifiers. Rather than creating cryptographically strong, unique tokens per session, the implementation allows multiple endpoints to authenticate using identical session identifiers. This design flaw—categorized under CWE-613 (Insufficient Session Expiration)—creates two distinct attack vectors: (1) session hijacking, where an attacker predicts valid session tokens to assume another user's identity, and (2) resource exhaustion, where bulk requests using valid sessions can degrade or disable backend services. The predictability of identifiers compounds the risk by eliminating the computational barrier normally associated with session token brute-forcing.

Business impact

Organizations operating charging station infrastructure face direct operational and security consequences. Unauthorized session access enables attackers to manipulate charging operations, redirect billing, or alter transaction logs. Denial-of-service attacks can render charging networks unavailable, disrupting customer revenue and damaging service reputation. For energy utilities and fleet operators, extended downtime translates to lost charging sessions, customer churn, and potential regulatory scrutiny. Additionally, session hijacking may expose customer payment information and location data, creating compliance liabilities under data protection regulations.

Affected systems

The vulnerability affects WebSocket-based charging station backend systems that rely on the vulnerable session management scheme. The source data does not enumerate specific vendor products; organizations should consult vendor advisories and audit their charging infrastructure deployments to determine exposure. Any system using the affected WebSocket backend implementation with the described session identifier generation mechanism is in scope.

Exploitability

This vulnerability is highly exploitable. It requires no authentication credentials, no special privileges, and no user interaction. An attacker needs only network access to the WebSocket endpoint and the ability to predict or enumerate session identifiers—a task made straightforward by the predictable identifier scheme. The attack can be automated and scaled, making it particularly attractive for both targeted session hijacking and indiscriminate denial-of-service campaigns. No additional complexity, such as race conditions or timing-dependent operations, is required.

Remediation

Remediation requires replacing the current session identifier mechanism with cryptographically secure, random tokens that are unique per session and unpredictable. Organizations should: (1) implement per-session token generation using a cryptographic random number generator, (2) enforce strict session expiration policies and implement session invalidation mechanisms, (3) add server-side session validation to reject reuse of tokens across multiple connections, and (4) implement rate limiting on session creation requests to mitigate denial-of-service attempts. Until patches are available, network segmentation and strict access control lists on WebSocket endpoints can provide temporary risk reduction.

Patch guidance

Verify the availability and version of patches from your charging station backend vendor. Apply patches in a staged manner, beginning with non-critical systems and development environments to validate compatibility. Ensure backend and WebSocket endpoint versions are coordinated to prevent interoperability issues post-patch. Security advisories from the vendor will contain specific version numbers and rollout timelines; prioritize systems facing external network exposure.

Detection guidance

Monitor WebSocket connections for anomalies indicative of session exploitation or reuse: (1) multiple simultaneous connections using identical session identifiers from different source IPs, (2) rapid successive session creation requests (pattern suggestive of identifier enumeration), (3) session tokens originating from unexpected or external networks, and (4) failed authentication attempts followed by successful access using the same session identifier. Implement logging at the session validation layer to capture token reuse. Network-based detection should flag bulk WebSocket connection attempts and unusual session token patterns in traffic.

Why prioritize this

This vulnerability merits immediate priority due to its high CVSS score (7.3), ease of exploitation, and direct impact on operational continuity and customer data security. The attack requires no privileges or complexity, affecting a system central to energy and transportation infrastructure. The dual nature of the threat—both authentication bypass and denial-of-service—creates compounding risk. Organizations should treat this as critical and begin remediation planning without delay.

Risk score, explained

The CVSS 3.1 score of 7.3 (HIGH) reflects the combination of network-based attack vector (AV:N), low attack complexity (AC:L), and no privilege or user interaction requirements (PR:N/UI:N). The confidentiality, integrity, and availability impacts are all rated as 'low' individually, but collectively represent meaningful compromise across all three CIA properties. The unchanged scope (S:U) indicates the vulnerability does not cross trust boundaries, limiting lateral blast radius but not reducing the severity of direct impact on affected services.

Frequently asked questions