BaselineWatch
Desk

CVE-2026-103415

9.3 critical SSVC exploitation: none Awaiting Analysis

When a TLS 1.3 client processes a HelloRetryRequest, it copies the server's cookie into its second ClientHello without checking that the cookie fits in the outgoing packet. Both the length and the contents of that cookie come from the peer, and the write happens before certificate authentication completes, so a malicious or compromised server can overwrite memory past the caller supplied TLS packet buffer without presenting a certificate. Only the client path is affected.

Fix

Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.

Change history 2

  1. StatusReceived → Awaiting AnalysisNVD modified 2026-10-15 14:41
  2. First seenCVSS 9.3NVD modified 2026-10-14 18:17

Affected (CPE criteria) 0

NVD has not attached CPE configurations yet.

References 2