CVE-2025-51862 describes an Insecure Direct Object Reference (IDOR) vulnerability found in the chat component of TelegAI, a platform accessible via telegai.com. This vulnerability allows an attacker to manipulate references to internal objects, specifically user conversations, without proper authorization checks. By exploiting this flaw, an attacker can tamper with other users' chat conversations, potentially altering or deleting messages. Furthermore, the vulnerability enables injection of malicious content and Cross-Site Scripting (XSS) payloads into the chat interface. Such XSS injections can be leveraged to conduct phishing attacks by displaying deceptive content to users, spoof user identities, or hijack user accounts by stealing session tokens or credentials. The vulnerability was reserved in mid-June 2025 and published in late July 2025, but no CVSS score or patch information is currently available. There are no known exploits in the wild at this time. The lack of authentication or authorization checks on object references in the chat system represents a critical security flaw that undermines confidentiality, integrity, and availability of user communications within TelegAI.

For European organizations using TelegAI, this vulnerability poses significant risks. The ability to tamper with conversations compromises the integrity and trustworthiness of communications, which can disrupt business operations and internal collaboration. Injection of malicious scripts can lead to widespread phishing campaigns targeting employees, resulting in credential theft and unauthorized access to sensitive systems. Account hijacking through XSS can escalate privileges or enable lateral movement within organizational networks. Given the increasing reliance on digital communication tools in Europe, exploitation of this vulnerability could lead to data breaches, regulatory non-compliance (e.g., GDPR violations), reputational damage, and financial losses. The threat is particularly concerning for sectors with high confidentiality requirements such as finance, healthcare, and government institutions.

To mitigate this vulnerability, European organizations should first verify if they are using TelegAI and identify the affected chat component versions. Immediate steps include restricting access to the chat system to trusted users and monitoring for unusual activity or message alterations. Organizations should work with TelegAI to obtain and apply security patches once available. In the interim, implementing Web Application Firewalls (WAFs) with rules to detect and block XSS payloads can reduce risk. Conducting regular security assessments and penetration testing focused on IDOR and XSS vulnerabilities in communication platforms is advised. User education on phishing awareness and multi-factor authentication (MFA) deployment can limit the impact of account hijacking attempts. Additionally, logging and alerting on suspicious chat modifications will aid in early detection of exploitation attempts.