CVE-2026-54874

Technical Description

Issue summary: Receiving a DTLS record for a future epoch while a handshake

is in progress causes OpenSSL to buffer far more memory than the record

itself requires.

Impact summary: A peer can use a small amount of network traffic to make an

OpenSSL DTLS endpoint retain a disproportionately large amount of memory,

which may lead to a Denial of Service.

CWE: CWE-405: Asymmetric Resource Consumption (Amplification)

Description: While a DTLS handshake is in progress, a peer may legitimately

have already moved on to the next epoch (for example, having sent its

ChangeCipherSpec and Finished messages) before the local endpoint has

processed the same transition, typically because of reordering on the

underlying UDP transport. OpenSSL buffers such early records so that they

can be processed once the local endpoint catches up.

Buffering a record currently retains the entire read buffer it arrived in,

which is sized to hold the largest possible DTLS record (around 16

kilobytes), rather than j

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References