Out-of-bounds Read Vulnerability in OpenSSL DTLS Handshake Logic
CVE-2026-84782

8.2HIGH

Key Information:

Vendor: OpenSSL
Status: OpenSSL
Vendor: CVE Published:; 29 September 2026

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📈 Score: 636📰 News Worthy

What is CVE-2026-84782?

CVE-2026-84782 is a vulnerability identified in the OpenSSL implementation relating to the Datagram Transport Layer Security (DTLS) protocol's handshake logic. OpenSSL is a widely used library for secure communication, primarily employed in various applications to facilitate encrypted links across networks. This specific vulnerability manifests due to improper handling during the retransmission of DTLS handshake messages, which can lead to out-of-bounds reading of memory. When a message transmission is suspended midway—usually due to the transport layer being unable to accept more data—the retransmission mechanism may inadvertently reuse buffer space that can lead to the exposure of potentially sensitive plaintext data or system instability. If exploited, this vulnerability can expose heap memory content to unauthorized peers or crash the application, resulting in Denial of Service for the affected service, which can severely disrupt business operations.

Potential impact of CVE-2026-84782

Data Exposure: The vulnerability allows leaked plaintext handshake data from heap memory, which may include sensitive information exchanged during secure communications. This could lead to the disclosure of encryption keys or other critical data, compromising the integrity and confidentiality of the communications.
Denial of Service (DoS): The flawed retransmission mechanism may cause applications to crash when they attempt to read from unmapped memory regions. This could render affected services unavailable, leading to operational downtime and potential revenue loss for organizations relying on these services.
Misleading Internal State: The faulty logic in the retransmission process can lead to inconsistencies in the application’s internal state. When the application attempts to resume processes depending on this state, it may encounter failures, further compounding the risk of operational disruptions and creating challenges in system recovery.