CVE-2026-5503
Published: Apr 9, 2026
Modified: Apr 10, 2026
Description
In TLSX_EchChangeSNI, the ctx->extensions branch set extensions unconditionally even when TLSX_Find returned NULL. This caused TLSX_UseSNI to attach the attacker-controlled publicName to the shared WOLFSSL_CTX when no inner SNI was configured. TLSX_EchRestoreSNI then failed to clean it up because its removal was gated on serverNameX != NULL. The inner ClientHello was sized before the pollution but written after it, causing TLSX_SNI_Write to memcpy 255 bytes past the allocation boundary.
| Vendor | Product | Versions |
|---|---|---|
wolfSSL | wolfSSL | affected 0 - <= 5.9.0 |
Weaknesses (CWE)
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