diff --git a/wolfcrypt/src/aes.c b/wolfcrypt/src/aes.c
index b7d43c33d13..02a6e1d4240 100644
--- a/wolfcrypt/src/aes.c
+++ b/wolfcrypt/src/aes.c
@@ -13661,10 +13661,12 @@ Aes* wc_AesNew_Label(const char* label, void* heap, int devId,
 
 int wc_AesDelete(Aes *aes, Aes** aes_p)
 {
+    void* heap;
     if (aes == NULL)
         return BAD_FUNC_ARG;
+    heap = aes->heap;
     wc_AesFree(aes);
-    XFREE(aes, aes->heap, DYNAMIC_TYPE_AES);
+    XFREE(aes, heap, DYNAMIC_TYPE_AES);
     if (aes_p != NULL)
         *aes_p = NULL;
     return 0;
diff --git a/wolfcrypt/src/ext_lms.c b/wolfcrypt/src/ext_lms.c
index cd354232034..c953abcfb38 100644
--- a/wolfcrypt/src/ext_lms.c
+++ b/wolfcrypt/src/ext_lms.c
@@ -861,6 +861,10 @@ int wc_LmsKey_Sign(LmsKey* key, byte * sig, word32 * sigSz, const byte * msg,
                                     sig, len, &key->info);
 
     if (!result) {
+        /* Erase any partial signature to prevent OTS key reuse if state
+         * is rolled back. */
+        ForceZero(sig, len);
+
         if (wc_LmsKey_SigsLeft(key) == 0) {
             WOLFSSL_MSG("error: LMS signatures exhausted");
             key->state = WC_LMS_STATE_NOSIGS;
diff --git a/wolfcrypt/src/hash.c b/wolfcrypt/src/hash.c
index b500d2145ef..86a01999a1b 100644
--- a/wolfcrypt/src/hash.c
+++ b/wolfcrypt/src/hash.c
@@ -866,12 +866,14 @@ wc_HashAlg* wc_HashNew(enum wc_HashType type, void* heap, int devId,
 
 int wc_HashDelete(wc_HashAlg *hash, wc_HashAlg **hash_p) {
     int ret;
+    void* heap;
     if (hash == NULL)
         return BAD_FUNC_ARG;
+    heap = hash->heap;
     ret = wc_HashFree(hash, hash->type);
     if (ret < 0)
         return ret;
-    XFREE(hash, hash->heap, DYNAMIC_TYPE_HASHES);
+    XFREE(hash, heap, DYNAMIC_TYPE_HASHES);
     if (hash_p != NULL)
         *hash_p = NULL;
     return 0;
diff --git a/wolfcrypt/src/hmac.c b/wolfcrypt/src/hmac.c
index edc16f1a5fb..8e8ad3ff3e2 100644
--- a/wolfcrypt/src/hmac.c
+++ b/wolfcrypt/src/hmac.c
@@ -1590,6 +1590,10 @@ int wolfSSL_GetHmacMaxSize(void)
         const  byte* localSalt;  /* either points to user input or tmp */
         word32 hashSz;
 
+        if (out == NULL || (inKey == NULL && inKeySz > 0)) {
+            return BAD_FUNC_ARG;
+        }
+
         ret = wc_HmacSizeByType(type);
         if (ret < 0) {
             return ret;
diff --git a/wolfcrypt/src/kdf.c b/wolfcrypt/src/kdf.c
index c6be3afc992..849b6dfa52f 100644
--- a/wolfcrypt/src/kdf.c
+++ b/wolfcrypt/src/kdf.c
@@ -1009,7 +1009,8 @@ int wc_SRTP_KDF(const byte* key, word32 keySz, const byte* salt, word32 saltSz,
 
     /* Validate parameters. */
     if ((key == NULL) || (keySz > AES_256_KEY_SIZE) || (salt == NULL) ||
-            (saltSz > WC_SRTP_MAX_SALT) || (kdrIdx < -1) || (kdrIdx > 24)) {
+            (saltSz > WC_SRTP_MAX_SALT) || (kdrIdx < -1) || (kdrIdx > 24) ||
+            ((kdrIdx >= 0) && (idx == NULL))) {
         ret = BAD_FUNC_ARG;
     }
 
@@ -1103,7 +1104,8 @@ int wc_SRTCP_KDF_ex(const byte* key, word32 keySz, const byte* salt, word32 salt
 
     /* Validate parameters. */
     if ((key == NULL) || (keySz > AES_256_KEY_SIZE) || (salt == NULL) ||
-            (saltSz > WC_SRTP_MAX_SALT) || (kdrIdx < -1) || (kdrIdx > 24)) {
+            (saltSz > WC_SRTP_MAX_SALT) || (kdrIdx < -1) || (kdrIdx > 24) ||
+            ((kdrIdx >= 0) && (idx == NULL))) {
         ret = BAD_FUNC_ARG;
     }
 
@@ -1194,7 +1196,7 @@ int wc_SRTP_KDF_label(const byte* key, word32 keySz, const byte* salt,
     /* Validate parameters. */
     if ((key == NULL) || (keySz > AES_256_KEY_SIZE) || (salt == NULL) ||
             (saltSz > WC_SRTP_MAX_SALT) || (kdrIdx < -1) || (kdrIdx > 24) ||
-            (outKey == NULL)) {
+            (outKey == NULL) || ((kdrIdx >= 0) && (idx == NULL))) {
         ret = BAD_FUNC_ARG;
     }
 
@@ -1267,7 +1269,7 @@ int wc_SRTCP_KDF_label(const byte* key, word32 keySz, const byte* salt,
     /* Validate parameters. */
     if ((key == NULL) || (keySz > AES_256_KEY_SIZE) || (salt == NULL) ||
             (saltSz > WC_SRTP_MAX_SALT) || (kdrIdx < -1) || (kdrIdx > 24) ||
-            (outKey == NULL)) {
+            (outKey == NULL) || ((kdrIdx >= 0) && (idx == NULL))) {
         ret = BAD_FUNC_ARG;
     }
 
diff --git a/wolfcrypt/src/wc_lms.c b/wolfcrypt/src/wc_lms.c
index f6aa7098c0c..402b2f3c5a4 100644
--- a/wolfcrypt/src/wc_lms.c
+++ b/wolfcrypt/src/wc_lms.c
@@ -1052,6 +1052,9 @@ int wc_LmsKey_Sign(LmsKey* key, byte* sig, word32* sigSz, const byte* msg,
             HSS_PRIVATE_KEY_LEN(key->params->hash_len), key->context);
 #endif
         if (rv != WC_LMS_RC_SAVED_TO_NV_MEMORY) {
+            /* Write to NV storage failed. Erase the signature from
+             * memory to prevent OTS key reuse if state is rolled back. */
+            ForceZero(sig, key->params->sig_len);
             ret = IO_FAILED_E;
         }
     }
diff --git a/wolfcrypt/src/wc_mlkem.c b/wolfcrypt/src/wc_mlkem.c
index 95fa76e0f8f..74c4260a1cb 100644
--- a/wolfcrypt/src/wc_mlkem.c
+++ b/wolfcrypt/src/wc_mlkem.c
@@ -337,10 +337,12 @@ MlKemKey* wc_MlKemKey_New(int type, void* heap, int devId)
 
 int wc_MlKemKey_Delete(MlKemKey* key, MlKemKey** key_p)
 {
+    void* heap;
     if (key == NULL)
         return BAD_FUNC_ARG;
+    heap = key->heap;
     wc_MlKemKey_Free(key);
-    XFREE(key, key->heap, DYNAMIC_TYPE_TMP_BUFFER);
+    XFREE(key, heap, DYNAMIC_TYPE_TMP_BUFFER);
     if (key_p != NULL)
         *key_p = NULL;
 
diff --git a/wolfcrypt/test/test.c b/wolfcrypt/test/test.c
index d639f523a44..b869dc19609 100644
--- a/wolfcrypt/test/test.c
+++ b/wolfcrypt/test/test.c
@@ -31466,7 +31466,18 @@ WOLFSSL_TEST_SUBROUTINE wc_test_ret_t hkdf_test(void)
 #endif /* !NO_SHA256 */
 #endif /* !NO_SHA || !NO_SHA256 */
 
-    return ret;
+#ifndef NO_SHA256
+    /* wc_HKDF_Extract bad arg: NULL out */
+    ret = wc_HKDF_Extract(WC_SHA256, NULL, 0, ikm1, (word32)sizeof(ikm1), NULL);
+    if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
+        return WC_TEST_RET_ENC_EC(ret);
+    /* wc_HKDF_Extract bad arg: NULL inKey with non-zero inKeySz */
+    ret = wc_HKDF_Extract(WC_SHA256, NULL, 0, NULL, 5, okm1);
+    if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
+        return WC_TEST_RET_ENC_EC(ret);
+#endif /* !NO_SHA256 */
+
+    return 0;
 }
 
 #endif /* HAVE_HKDF */
@@ -33402,6 +33413,24 @@ WOLFSSL_TEST_SUBROUTINE wc_test_ret_t srtpkdf_test(void)
     if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
         ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out);
 
+    /* kdrIdx >= 0 requires non-NULL idx. */
+    ret = wc_SRTP_KDF(tv[i].key, tv[i].keySz, tv[i].salt, tv[i].saltSz,
+        0, NULL, keyE, tv[i].keSz, keyA, tv[i].kaSz, keyS, tv[i].ksSz);
+    if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out);
+    ret = wc_SRTCP_KDF(tv[i].key, tv[i].keySz, tv[i].salt, tv[i].saltSz,
+        0, NULL, keyE, tv[i].keSz, keyA, tv[i].kaSz, keyS, tv[i].ksSz);
+    if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out);
+    ret = wc_SRTP_KDF_label(tv[i].key, tv[i].keySz, tv[i].salt, tv[i].saltSz,
+        0, NULL, WC_SRTP_LABEL_ENCRYPTION, keyE, tv[i].keSz);
+    if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out);
+    ret = wc_SRTCP_KDF_label(tv[i].key, tv[i].keySz, tv[i].salt, tv[i].saltSz,
+        0, NULL, WC_SRTCP_LABEL_ENCRYPTION, keyE, tv[i].keSz);
+    if (ret != WC_NO_ERR_TRACE(BAD_FUNC_ARG))
+        ERROR_OUT(WC_TEST_RET_ENC_EC(ret), out);
+
     ret = wc_SRTP_KDF(tv[i].key, tv[i].keySz, tv[i].salt, tv[i].saltSz,
         tv[i].kdfIdx, tv[i].index, NULL, tv[i].keSz, keyA, tv[i].kaSz,
         keyS, tv[i].ksSz);