diff --git a/ChangeLog b/ChangeLog
index 932e28065f..2bc462fb07 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -106,6 +106,8 @@ Security
    * Change default choice of DHE parameters from untrustworthy RFC 5114
      to RFC 3526 containing parameters generated in a nothing-up-my-sleeve
      manner.
+   * Fix a buffer overread in ssl_parse_server_key_exchange() that could cause
+     a crash on invalid input.
 
 Features
    * Allow comments in test data files.
@@ -240,6 +242,8 @@ Bugfix
    * In mbedtls_entropy_free(), properly free the message digest context.
    * Fix status handshake status message in programs/ssl/dtls_client.c. Found
      and fixed by muddog.
+   * Fix a possible arithmetic overflow in ssl_parse_server_key_exchange()
+     that could cause a key exchange to fail on valid data.
 
 Changes
    * Extend cert_write example program by options to set the certificate version
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 2534346a49..2eec7665b1 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2478,10 +2478,17 @@ static int ssl_parse_server_key_exchange( mbedtls_ssl_context *ssl )
         /*
          * Read signature
          */
+        if( p > end - 2 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
+            mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
+                                            MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR );
+            return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+        }
         sig_len = ( p[0] << 8 ) | p[1];
         p += 2;
 
-        if( end != p + sig_len )
+        if( p != end - sig_len )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server key exchange message" ) );
             mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,