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CVE-2026-63566: Product identification pending

Severity

8.7 (HIGH)

Affected versions

Before 2.7.0

Fixed version

2.7.0

Patch status

Patched

Published

2026-10-02T07:16:36.973

Modified

2026-10-02T07:16:36.973

Why it matters

This matters because the affected product may allow code execution. Prioritize systems that are internet-facing or have privileged access to other infrastructure.

Recommended admin actions

• Review and patch based on exposure, asset criticality, and business impact.
• Compare installed versions against the affected version range in the advisory.
• Treat internet-facing systems as higher priority.
• Review logs for suspicious activity related to the affected application or component.

Technical summary

Memory allocation with excessive size value in the DTLS handshake reassembly (DtlsReliableHandshake, DtlsReassembler) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote unauthenticated DTLS peer to cause a denial of service through memory exhaustion via crafted handshake message fragments, because the reassembly buffer for each incoming handshake message was allocated at the 24-bit length declared in the fragment header, without the check against the peer's maximum handshake message size that TLS already applied. A fragment carrying no payload can force an allocation of almost 16 MB, for each of up to 16 pending messages per handshake, before the handshake is authenticated. DTLS servers and DTLS clients are both affected; TLS is not.

View the official NVD record for CVE-2026-63566

CVE data is sourced from NVD/CNA records and optional enrichment. Validate against the vendor advisory before taking production action.