CVE-2026-103415
CRITICAL—CVSS v3
—CVSS v2
0.28%
EPSS (exploit probability)
CWE-787CWE
Description
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.
Affected routers (0)
No routers currently mapped to this CVE in our database.