diff --git a/ChangeLog.d/ssl_decrypt_buf-short_record.txt b/ChangeLog.d/ssl_decrypt_buf-short_record.txt
new file mode 100644
index 0000000000000000000000000000000000000000..88dc219acb506c4ad494eaf6f2e43f04868e1cf2
--- /dev/null
+++ b/ChangeLog.d/ssl_decrypt_buf-short_record.txt
@@ -0,0 +1,3 @@
+Security
+   * Fix a buffer overread when parsing short TLS application data records in
+     null-cipher cipher suites. Credit to OSS-Fuzz.
\ No newline at end of file
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 51eb4619c68c2d0bd4249c43a2fff83bc151ba25..be4e333db035bf513de6ef04c3936686f25a2747 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -1038,6 +1038,13 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_STREAM)
     if( mode == MBEDTLS_MODE_STREAM )
     {
+        if (rec->data_len < transform->maclen) {
+            MBEDTLS_SSL_DEBUG_MSG(1,
+                                  ("Record too short for MAC:"
+                                   " %" MBEDTLS_PRINTF_SIZET " < %" MBEDTLS_PRINTF_SIZET,
+                                   rec->data_len, transform->maclen));
+            return MBEDTLS_ERR_SSL_INVALID_MAC;
+        }
         padlen = 0;
         if( ( ret = mbedtls_cipher_crypt( &transform->cipher_ctx_dec,
                                    transform->iv_dec,
@@ -1430,7 +1437,7 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
         unsigned char mac_expect[MBEDTLS_SSL_MAC_ADD];
         unsigned char mac_peer[MBEDTLS_SSL_MAC_ADD];
 
-        /* If the initial value of padlen was such that
+        /* For CBC+MAC, If the initial value of padlen was such that
          * data_len < maclen + padlen + 1, then padlen
          * got reset to 1, and the initial check
          * data_len >= minlen + maclen + 1
@@ -1442,6 +1449,9 @@ int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
          * subtracted either padlen + 1 (if the padding was correct)
          * or 0 (if the padding was incorrect) since then,
          * hence data_len >= maclen in any case.
+         *
+         * For stream ciphers, we checked above that
+         * data_len >= maclen.
          */
         rec->data_len -= transform->maclen;
         ssl_extract_add_data_from_record( add_data, &add_data_len, rec,