From 7a264162b82bf8470dee979886d7cfe8956af50f Mon Sep 17 00:00:00 2001
From: Juliusz Sosinowicz <juliusz@wolfssl.com>
Date: Mon, 9 Mar 2026 17:21:01 +0100
Subject: [PATCH] wc_ChaCha20Poly1305_Decrypt: clear unauthed plaintext

F-452
---
 wolfcrypt/src/chacha20_poly1305.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/wolfcrypt/src/chacha20_poly1305.c b/wolfcrypt/src/chacha20_poly1305.c
index 8911b4d53d..a7acd6acfa 100644
--- a/wolfcrypt/src/chacha20_poly1305.c
+++ b/wolfcrypt/src/chacha20_poly1305.c
@@ -119,6 +119,10 @@ int wc_ChaCha20Poly1305_Decrypt(
     if (ret == 0)
         ret = wc_ChaCha20Poly1305_CheckTag(inAuthTag, calculatedAuthTag);
 
+    if (ret != 0) {
+        /* zero plaintext on error */
+        ForceZero(outPlaintext, inCiphertextLen);
+    }
     WC_FREE_VAR_EX(aead, NULL, DYNAMIC_TYPE_TMP_BUFFER);
 
     return ret;