diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c
index c8ed722ab157144b187091c16ac972041b0be50e..54075ae0e69bda34e69dab69d369799a05306637 100644
--- a/ssl/statem/extensions.c
+++ b/ssl/statem/extensions.c
@@ -421,8 +421,9 @@ int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
  * stored in |*res| on success. In the event of an error the alert type to use
  * is stored in |*al|. We don't actually process the content of the extensions
  * yet, except to check their types. This function also runs the initialiser
- * functions for all known extensions (whether we have collected them or not).
- * If successful the caller is responsible for freeing the contents of |*res|.
+ * functions for all known extensions if |init| is nonzero (whether we have
+ * collected them or not). If successful the caller is responsible for freeing
+ * the contents of |*res|.
  *
  * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
  * more than one extension of the same type in a ClientHello or ServerHello.
@@ -432,7 +433,8 @@ int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx)
  * extensions that we know about. We ignore others.
  */
 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
-                           RAW_EXTENSION **res, int *al, size_t *len)
+                           RAW_EXTENSION **res, int *al, size_t *len,
+                           int init)
 {
     PACKET extensions = *packet;
     size_t i = 0;
@@ -490,16 +492,19 @@ int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
         }
     }
 
-    /*
-     * Initialise all known extensions relevant to this context, whether we have
-     * found them or not
-     */
-    for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
-        if(thisexd->init != NULL && (thisexd->context & context) != 0
-                && extension_is_relevant(s, thisexd->context, context)
-                && !thisexd->init(s, context)) {
-            *al = SSL_AD_INTERNAL_ERROR;
-            goto err;
+    if (init) {
+        /*
+         * Initialise all known extensions relevant to this context,
+         * whether we have found them or not
+         */
+        for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs);
+             i++, thisexd++) {
+            if (thisexd->init != NULL && (thisexd->context & context) != 0 &&
+                extension_is_relevant(s, thisexd->context, context) &&
+                !thisexd->init(s, context)) {
+                *al = SSL_AD_INTERNAL_ERROR;
+                goto err;
+            }
         }
     }
 
@@ -578,14 +583,14 @@ int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
 
 /*
  * Parse all remaining extensions that have not yet been parsed. Also calls the
- * finalisation for all extensions at the end, whether we collected them or not.
- * Returns 1 for success or 0 for failure. If we are working on a Certificate
- * message then we also pass the Certificate |x| and its position in the
- * |chainidx|, with 0 being the first certificate. On failure, |*al| is
- * populated with a suitable alert code.
+ * finalisation for all extensions at the end if |fin| is nonzero, whether we
+ * collected them or not. Returns 1 for success or 0 for failure. If we are
+ * working on a Certificate message then we also pass the Certificate |x| and
+ * its position in the |chainidx|, with 0 being the first certificate. On
+ * failure, |*al| is populated with a suitable alert code.
  */
 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
-                             size_t chainidx, int *al)
+                             size_t chainidx, int *al, int fin)
 {
     size_t i, numexts = OSSL_NELEM(ext_defs);
     const EXTENSION_DEFINITION *thisexd;
@@ -599,15 +604,17 @@ int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x,
             return 0;
     }
 
-    /*
-     * Finalise all known extensions relevant to this context, whether we have
-     * found them or not
-     */
-    for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) {
-        if(thisexd->final != NULL
-                && (thisexd->context & context) != 0
-                && !thisexd->final(s, context, exts[i].present, al))
-            return 0;
+    if (fin) {
+        /*
+         * Finalise all known extensions relevant to this context,
+         * whether we have found them or not
+         */
+        for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs);
+             i++, thisexd++) {
+            if (thisexd->final != NULL && (thisexd->context & context) != 0 &&
+                !thisexd->final(s, context, exts[i].present, al))
+                return 0;
+        }
     }
 
     return 1;
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index ab77ba05e9ff4416e56f36f3a3c44bb1a84131ee..0b4931d6d0812d9644258851e0218f8d78206d40 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -1373,7 +1373,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
 
     context = SSL_IS_TLS13(s) ? SSL_EXT_TLS1_3_SERVER_HELLO
                               : SSL_EXT_TLS1_2_SERVER_HELLO;
-    if (!tls_collect_extensions(s, &extpkt, context, &extensions, &al, NULL))
+    if (!tls_collect_extensions(s, &extpkt, context, &extensions, &al, NULL, 1))
         goto f_err;
 
     s->hit = 0;
@@ -1525,7 +1525,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     }
 #endif
 
-    if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, &al))
+    if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, &al, 1))
         goto f_err;
 
 #ifndef OPENSSL_NO_SCTP
@@ -1616,9 +1616,9 @@ static MSG_PROCESS_RETURN tls_process_hello_retry_request(SSL *s, PACKET *pkt)
     }
 
     if (!tls_collect_extensions(s, &extpkt, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
-                                &extensions, &al, NULL)
+                                &extensions, &al, NULL, 1)
             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
-                                         extensions, NULL, 0, &al))
+                                         extensions, NULL, 0, &al, 1))
         goto f_err;
 
     OPENSSL_free(extensions);
@@ -1711,9 +1711,10 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
             }
             if (!tls_collect_extensions(s, &extensions,
                                         SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
-                                        &al, NULL)
+                                        &al, NULL, chainidx == 0)
                     || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
-                                                 rawexts, x, chainidx, &al)) {
+                                                 rawexts, x, chainidx, &al,
+                                                 !PACKET_remaining(pkt))) {
                 OPENSSL_free(rawexts);
                 goto f_err;
             }
@@ -2340,9 +2341,9 @@ MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
         }
         if (!tls_collect_extensions(s, &extensions,
                                     SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
-                                    &rawexts, &al, NULL)
+                                    &rawexts, &al, NULL, 1)
             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
-                                         rawexts, NULL, 0, &al)) {
+                                         rawexts, NULL, 0, &al, 1)) {
             OPENSSL_free(rawexts);
             goto err;
         }
@@ -2501,10 +2502,10 @@ MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
         if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
                 || !tls_collect_extensions(s, &extpkt,
                                            SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
-                                           &exts, &al, NULL)
+                                           &exts, &al, NULL, 1)
                 || !tls_parse_all_extensions(s,
                                              SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
-                                             exts, NULL, 0, &al)) {
+                                             exts, NULL, 0, &al, 1)) {
             SSLerr(SSL_F_TLS_PROCESS_NEW_SESSION_TICKET, SSL_R_BAD_EXTENSION);
             goto f_err;
         }
@@ -3464,9 +3465,9 @@ static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
 
     if (!tls_collect_extensions(s, &extensions,
                                 SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, &rawexts,
-                                &al, NULL)
+                                &al, NULL, 1)
             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
-                                         rawexts, NULL, 0, &al))
+                                         rawexts, NULL, 0, &al, 1))
         goto err;
 
     OPENSSL_free(rawexts);
diff --git a/ssl/statem/statem_locl.h b/ssl/statem/statem_locl.h
index 2352c6a11ea76585eade8364cb2ef8cd0ebe166e..3b9311e02f5b1e7065c7c51222c947a9b95f3f24 100644
--- a/ssl/statem/statem_locl.h
+++ b/ssl/statem/statem_locl.h
@@ -156,12 +156,13 @@ MSG_PROCESS_RETURN tls_process_end_of_early_data(SSL *s, PACKET *pkt);
 __owur int extension_is_relevant(SSL *s, unsigned int extctx,
                                  unsigned int thisctx);
 __owur int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
-                                  RAW_EXTENSION **res, int *al, size_t *len);
+                                  RAW_EXTENSION **res, int *al, size_t *len,
+                                  int init);
 __owur int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
                                RAW_EXTENSION *exts,  X509 *x, size_t chainidx,
                                int *al);
 __owur int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts,
-                                    X509 *x, size_t chainidx, int *al);
+                                    X509 *x, size_t chainidx, int *al, int fin);
 __owur int should_add_extension(SSL *s, unsigned int extctx,
                                 unsigned int thisctx, int max_version);
 __owur int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c
index d751502aba726fa2647c637d7c6e5f52ae8bc1c8..f6ecbf700654643553600d27243882cda95919de 100644
--- a/ssl/statem/statem_srvr.c
+++ b/ssl/statem/statem_srvr.c
@@ -1426,7 +1426,7 @@ MSG_PROCESS_RETURN tls_process_client_hello(SSL *s, PACKET *pkt)
     extensions = clienthello->extensions;
     if (!tls_collect_extensions(s, &extensions, SSL_EXT_CLIENT_HELLO,
                                 &clienthello->pre_proc_exts, &al,
-                                &clienthello->pre_proc_exts_len)) {
+                                &clienthello->pre_proc_exts_len, 1)) {
         /* SSLerr already been called */
         goto f_err;
     }
@@ -1690,7 +1690,7 @@ static int tls_early_post_process_client_hello(SSL *s, int *pal)
 
     /* TLS extensions */
     if (!tls_parse_all_extensions(s, SSL_EXT_CLIENT_HELLO,
-                                  clienthello->pre_proc_exts, NULL, 0, &al)) {
+                                  clienthello->pre_proc_exts, NULL, 0, &al, 1)) {
         SSLerr(SSL_F_TLS_EARLY_POST_PROCESS_CLIENT_HELLO, SSL_R_PARSE_TLSEXT);
         goto err;
     }
@@ -3217,9 +3217,10 @@ MSG_PROCESS_RETURN tls_process_client_certificate(SSL *s, PACKET *pkt)
             }
             if (!tls_collect_extensions(s, &extensions,
                                         SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
-                                        &al, NULL)
+                                        &al, NULL, chainidx == 0)
                     || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
-                                                 rawexts, x, chainidx, &al)) {
+                                                 rawexts, x, chainidx, &al,
+                                                 !PACKET_remaining(&spkt))) {
                 OPENSSL_free(rawexts);
                 goto f_err;
             }