{"id":"CVE-2026-103415","title":"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","summary":"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 pe…","severity":"none","cwe":["CWE-787"],"published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T18:17:19.790","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-103415","references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-5pv3-rhf5-gwgq","label":"emo@eclipse.org"},{"url":"https://gitlab.eclipse.org/security/cve-assignment/-/work_items/357","label":"emo@eclipse.org"}],"tags":["nvd"],"ingestedAt":"2026-10-14T18:47:39.307Z","slug":"CVE-2026-103415","body":"## Overview\n\nWhen 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.\n\n\n\nOnly the client path is affected.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}