diff --git a/ChangeLog.d/bugfix_PR3405 b/ChangeLog.d/bugfix_PR3405
new file mode 100644
index 0000000..73c57c0
--- /dev/null
+++ b/ChangeLog.d/bugfix_PR3405
@@ -0,0 +1,5 @@
+Bugfix
+   * Update iv and len context pointers manually when reallocating buffers
+     using the MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH feature. This caused issues
+     when receiving a connection with CID, when these fields were shifted
+     in ssl_parse_record_header().
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 77d2757..250ef98 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3686,11 +3686,13 @@
     /* If the buffers are too small - reallocate */
     {
         int modified = 0;
-        size_t written_in = 0;
-        size_t written_out = 0;
+        size_t written_in = 0, iv_offset_in = 0, len_offset_in = 0;
+        size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
         if( ssl->in_buf != NULL )
         {
             written_in = ssl->in_msg - ssl->in_buf;
+            iv_offset_in = ssl->in_iv - ssl->in_buf;
+            len_offset_in = ssl->in_len - ssl->in_buf;
             if( ssl->in_buf_len < MBEDTLS_SSL_IN_BUFFER_LEN )
             {
                 if( resize_buffer( &ssl->in_buf, MBEDTLS_SSL_IN_BUFFER_LEN,
@@ -3709,6 +3711,8 @@
         if( ssl->out_buf != NULL )
         {
             written_out = ssl->out_msg - ssl->out_buf;
+            iv_offset_out = ssl->out_iv - ssl->out_buf;
+            len_offset_out = ssl->out_len - ssl->out_buf;
             if( ssl->out_buf_len < MBEDTLS_SSL_OUT_BUFFER_LEN )
             {
                 if( resize_buffer( &ssl->out_buf, MBEDTLS_SSL_OUT_BUFFER_LEN,
@@ -3728,9 +3732,14 @@
             /* Update pointers here to avoid doing it twice. */
             mbedtls_ssl_reset_in_out_pointers( ssl );
             /* Fields below might not be properly updated with record
-            * splitting, so they are manually updated here. */
+             * splitting or with CID, so they are manually updated here. */
             ssl->out_msg = ssl->out_buf + written_out;
+            ssl->out_len = ssl->out_buf + len_offset_out;
+            ssl->out_iv = ssl->out_buf + iv_offset_out;
+
             ssl->in_msg = ssl->in_buf + written_in;
+            ssl->in_len = ssl->in_buf + len_offset_in;
+            ssl->in_iv = ssl->in_buf + iv_offset_in;
         }
     }
 #endif
@@ -5962,14 +5971,15 @@
     {
         int modified = 0;
         uint32_t buf_len = mbedtls_ssl_get_input_buflen( ssl );
-        size_t written_in = 0;
-        size_t written_out = 0;
+        size_t written_in = 0, iv_offset_in = 0, len_offset_in = 0;
+        size_t written_out = 0, iv_offset_out = 0, len_offset_out = 0;
         if( ssl->in_buf != NULL )
         {
             written_in = ssl->in_msg - ssl->in_buf;
+            iv_offset_in = ssl->in_iv - ssl->in_buf;
+            len_offset_in = ssl->in_len - ssl->in_buf;
             if( ssl->in_buf_len > buf_len && ssl->in_left < buf_len )
             {
-                written_in = ssl->in_msg - ssl->in_buf;
                 if( resize_buffer( &ssl->in_buf, buf_len, &ssl->in_buf_len ) != 0 )
                 {
                     MBEDTLS_SSL_DEBUG_MSG( 1, ( "input buffer resizing failed - out of memory" ) );
@@ -5987,6 +5997,8 @@
         if(ssl->out_buf != NULL )
         {
             written_out = ssl->out_msg - ssl->out_buf;
+            iv_offset_out = ssl->out_iv - ssl->out_buf;
+            len_offset_out = ssl->out_len - ssl->out_buf;
             if( ssl->out_buf_len > mbedtls_ssl_get_output_buflen( ssl ) &&
                 ssl->out_left < buf_len )
             {
@@ -6006,9 +6018,14 @@
             /* Update pointers here to avoid doing it twice. */
             mbedtls_ssl_reset_in_out_pointers( ssl );
             /* Fields below might not be properly updated with record
-             * splitting, so they are manually updated here. */
+             * splitting or with CID, so they are manually updated here. */
             ssl->out_msg = ssl->out_buf + written_out;
+            ssl->out_len = ssl->out_buf + len_offset_out;
+            ssl->out_iv = ssl->out_buf + iv_offset_out;
+
             ssl->in_msg = ssl->in_buf + written_in;
+            ssl->in_len = ssl->in_buf + len_offset_in;
+            ssl->in_iv = ssl->in_buf + iv_offset_in;
         }
     }
 #endif
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 3c185e0..5594c3d 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -2201,6 +2201,32 @@
             -c "ignoring unexpected CID" \
             -s "ignoring unexpected CID"
 
+requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
+requires_config_enabled MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
+run_test    "Connection ID: Cli+Srv enabled, variable buffer lengths, MFL=512" \
+            "$P_SRV dtls=1 cid=1 cid_val=dead debug_level=2" \
+            "$P_CLI force_ciphersuite="TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" max_frag_len=512 dtls=1 cid=1 cid_val=beef" \
+            0 \
+            -c "(initial handshake) Peer CID (length 2 Bytes): de ad" \
+            -s "(initial handshake) Peer CID (length 2 Bytes): be ef" \
+            -s "(initial handshake) Use of Connection ID has been negotiated" \
+            -c "(initial handshake) Use of Connection ID has been negotiated" \
+            -s "Reallocating in_buf" \
+            -s "Reallocating out_buf"
+
+requires_config_enabled MBEDTLS_SSL_DTLS_CONNECTION_ID
+requires_config_enabled MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
+run_test    "Connection ID: Cli+Srv enabled, variable buffer lengths, MFL=1024" \
+            "$P_SRV dtls=1 cid=1 cid_val=dead debug_level=2" \
+            "$P_CLI force_ciphersuite="TLS-ECDHE-ECDSA-WITH-AES-128-CCM-8" max_frag_len=1024 dtls=1 cid=1 cid_val=beef" \
+            0 \
+            -c "(initial handshake) Peer CID (length 2 Bytes): de ad" \
+            -s "(initial handshake) Peer CID (length 2 Bytes): be ef" \
+            -s "(initial handshake) Use of Connection ID has been negotiated" \
+            -c "(initial handshake) Use of Connection ID has been negotiated" \
+            -s "Reallocating in_buf" \
+            -s "Reallocating out_buf"
+
 # Tests for Encrypt-then-MAC extension
 
 run_test    "Encrypt then MAC: default" \