diff --git a/.wolfssl_known_macro_extras b/.wolfssl_known_macro_extras
index ce0c7faa743..3be2bfaa0ae 100644
--- a/.wolfssl_known_macro_extras
+++ b/.wolfssl_known_macro_extras
@@ -916,6 +916,7 @@ WOLFSSL_IMX6_CAAM_BLOB
 WOLFSSL_IMX6_CAAM_RNG
 WOLFSSL_IMXRT_DCP
 WOLFSSL_ISOTP
+WOLFSSL_KEEP_HOST_HEADER_PROBES
 WOLFSSL_KEIL
 WOLFSSL_KEIL_NET
 WOLFSSL_KYBER_NO_DECAPSULATE
diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd80922b710..69375d09fba 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -101,6 +101,7 @@ check_include_file("time.h" HAVE_TIME_H)
 check_include_file("sys/ioctl.h" HAVE_SYS_IOCTL_H)
 check_include_file("sys/socket.h" HAVE_SYS_SOCKET_H)
 check_include_file("sys/time.h" HAVE_SYS_TIME_H)
+check_include_file("sys/un.h" HAVE_SYS_UN_H)
 check_include_file("errno.h" HAVE_ERRNO_H)
 check_include_file("dlfcn.h" HAVE_DLFCN_H)
 check_include_file("inttypes.h" HAVE_INTTYPES_H)
@@ -113,13 +114,21 @@ check_include_file("sys/stat.h" HAVE_SYS_STAT_H)
 check_include_file("sys/types.h" HAVE_SYS_TYPES_H)
 check_include_file("unistd.h" HAVE_UNISTD_H)
 
-# types.h depends on HAVE_LIMITS_H, and it is defined in options.h (rather than
-# config.h) so that applications consuming wolfSSL headers see it. The in-tree
-# build, however, is configured through config.h/compile definitions and does
-# not include options.h, so define it here as well.
+# types.h depends on HAVE_LIMITS_H, and callbacks.h sizes WOLFSSL_TIMEVAL with
+# HAVE_SYS_TIME_H. Both are defined in options.h (rather than config.h) so that
+# applications consuming wolfSSL headers see the same value the library was
+# built with. The in-tree build, however, is configured through
+# config.h/compile definitions and does not include options.h, so define them
+# here as well.
 if(HAVE_LIMITS_H)
     add_definitions("-DHAVE_LIMITS_H")
 endif()
+if(HAVE_SYS_TIME_H)
+    add_definitions("-DHAVE_SYS_TIME_H")
+endif()
+if(HAVE_SYS_UN_H)
+    add_definitions("-DHAVE_SYS_UN_H")
+endif()
 
 include(CheckFunctionExists)
 
diff --git a/cmake/config.in b/cmake/config.in
index 6054b6dbe7b..c5a04f7c18a 100644
--- a/cmake/config.in
+++ b/cmake/config.in
@@ -34,9 +34,6 @@
 /* Define to 1 if you have the <string.h> header file. */
 #cmakedefine HAVE_STRING_H @HAVE_STRING_H@
 
-/* Define to 1 if you have the <sys/time.h> header file. */
-#cmakedefine HAVE_SYS_TIME_H @HAVE_SYS_TIME_H@
-
 /* Define to 1 if you have the <Security/SecTrustSettings.h> header file. */
 #cmakedefine HAVE_SECURITY_SECTRUSTSETTINGS_H @HAVE_SECURITY_SECTRUSTSETTINGS_H@
 
diff --git a/cmake/options.h.in b/cmake/options.h.in
index 0c6de3c9d48..ac9bc57f4de 100644
--- a/cmake/options.h.in
+++ b/cmake/options.h.in
@@ -41,6 +41,12 @@ extern "C" {
 /* Since types.h depends on HAVE_LIMITS_H, we must define it in options.h. */
 #undef HAVE_LIMITS_H
 #cmakedefine HAVE_LIMITS_H @HAVE_LIMITS_H@
+/* callbacks.h sizes WOLFSSL_TIMEVAL with HAVE_SYS_TIME_H, so it must be in
+ * options.h too. */
+#undef HAVE_SYS_TIME_H
+#cmakedefine HAVE_SYS_TIME_H @HAVE_SYS_TIME_H@
+#undef HAVE_SYS_UN_H
+#cmakedefine HAVE_SYS_UN_H @HAVE_SYS_UN_H@
 #undef ASIO_USE_WOLFSSL
 #cmakedefine ASIO_USE_WOLFSSL
 #undef BOOST_ASIO_USE_WOLFSSL
diff --git a/configure.ac b/configure.ac
index 9bf3b9c245e..971249f17b1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -224,6 +224,13 @@ fi
 AC_CHECK_HEADERS([arpa/inet.h fcntl.h netdb.h netinet/in.h stddef.h time.h sys/ioctl.h sys/socket.h sys/time.h errno.h sys/un.h ctype.h sys/random.h])
 # Special case: Since types.h depends on HAVE_LIMITS_H, we must define it in options.h.
 AC_CHECK_HEADER([limits.h], [AM_CPPFLAGS="$AM_CPPFLAGS -DHAVE_LIMITS_H=1"], [])
+# Special case: these gate the layout of public types in installed headers
+# (union WOLFSSL_BIO_ADDR in wolfio.h, WOLFSSL_TIMEVAL in callbacks.h), so
+# applications must see the same value the library was built with. These stay
+# in AC_CHECK_HEADERS above as well: only the plural form defines them in
+# confdefs.h, which the AC_CHECK_DECLS prologue below needs to see sys/time.h.
+AC_CHECK_HEADER([sys/un.h], [AM_CPPFLAGS="$AM_CPPFLAGS -DHAVE_SYS_UN_H=1"], [])
+AC_CHECK_HEADER([sys/time.h], [AM_CPPFLAGS="$AM_CPPFLAGS -DHAVE_SYS_TIME_H=1"], [])
 AC_CHECK_LIB([network],[socket])
 AC_C_BIGENDIAN
 AC_C___ATOMIC
diff --git a/src/internal.c b/src/internal.c
index fb6c54b1bbf..cdfa6fb3cfc 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -14630,11 +14630,11 @@ int CheckHostName(DecodedCert* dCert, const char *domainName,
     return ret;
 }
 
-int CheckIPAddr(DecodedCert* dCert, const char* ipasc)
+int CheckIPAddr(DecodedCert* dCert, const char* ipasc, size_t ipascLen)
 {
     WOLFSSL_MSG("Checking IPAddr");
 
-    return CheckHostName(dCert, ipasc, (size_t)XSTRLEN(ipasc), 0, 1);
+    return CheckHostName(dCert, ipasc, ipascLen, 0, 1);
 }
 
 
@@ -16057,6 +16057,9 @@ int DoVerifyCallback(WOLFSSL_CERT_MANAGER* cm, WOLFSSL* ssl, int cert_err,
 #if defined(OPENSSL_EXTRA)
     /* Perform domain and IP check only for the leaf certificate */
     if (args->certIdx == 0) {
+        size_t ipascLen = ((ssl != NULL) && (ssl->param != NULL)) ?
+                              XSTRLEN(ssl->param->ipasc) : 0;
+
         /* perform domain name check on the peer certificate */
         if (args->dCertInit && args->dCert && (ssl != NULL) &&
                 ssl->param && ssl->param->hostName[0]) {
@@ -16097,8 +16100,8 @@ int DoVerifyCallback(WOLFSSL_CERT_MANAGER* cm, WOLFSSL* ssl, int cert_err,
 
         /* perform IP address check on the peer certificate */
         if ((args->dCertInit != 0) && (args->dCert != NULL) && (ssl != NULL) &&
-            (ssl->param != NULL) && (XSTRLEN(ssl->param->ipasc) > 0)) {
-            if (CheckIPAddr(args->dCert, ssl->param->ipasc) != 0) {
+            (ssl->param != NULL) && (ipascLen > 0)) {
+            if (CheckIPAddr(args->dCert, ssl->param->ipasc, ipascLen) != 0) {
                 if (cert_err == 0) {
                     ret = IPADDR_MISMATCH;
                     WOLFSSL_ERROR_VERBOSE(ret);
@@ -18920,7 +18923,8 @@ int ProcessPeerCerts(WOLFSSL* ssl, byte* input, word32* inOutIdx,
 #ifndef OPENSSL_EXTRA
                 if (!ssl->options.verifyNone && ssl->buffers.ipasc.buffer) {
                     if (CheckIPAddr(args->dCert,
-                            (const char*)ssl->buffers.ipasc.buffer) != 0) {
+                            (const char*)ssl->buffers.ipasc.buffer,
+                            (size_t)ssl->buffers.ipasc.length) != 0) {
                         WOLFSSL_MSG("IPAddr match on alt names failed");
                         ret = IPADDR_MISMATCH;
                         WOLFSSL_ERROR_VERBOSE(ret);
diff --git a/src/x509.c b/src/x509.c
index e177f78dbfb..d9e948fe943 100644
--- a/src/x509.c
+++ b/src/x509.c
@@ -15943,10 +15943,7 @@ int wolfSSL_X509_check_host(WOLFSSL_X509 *x, const char *chk, size_t chklen,
     }
 
 #ifdef WOLFSSL_IP_ALT_NAME
-    /* chk is length delimited and may not be NUL terminated, so check it
-     * against the iPAddress entries directly rather than through the
-     * NUL terminated CheckIPAddr helper. */
-    ret = CheckHostName(dCert, (char *)chk, chklen, 0, 1);
+    ret = CheckIPAddr(dCert, (char *)chk, chklen);
     if (ret == 0) {
         goto out;
     }
@@ -16001,7 +15998,7 @@ int wolfSSL_X509_check_ip_asc(WOLFSSL_X509 *x, const char *ipasc,
             ret = WOLFSSL_FAILURE;
         }
         else {
-            ret = CheckIPAddr(dCert, ipasc);
+            ret = CheckIPAddr(dCert, ipasc, (size_t)XSTRLEN(ipasc));
             if (ret != 0) {
                 ret = WOLFSSL_FAILURE;
             }
diff --git a/tests/api/test_ossl_x509.c b/tests/api/test_ossl_x509.c
index b262b721422..dabbe81a29c 100644
--- a/tests/api/test_ossl_x509.c
+++ b/tests/api/test_ossl_x509.c
@@ -422,6 +422,20 @@ int test_wolfSSL_X509_check_host(void)
     ExpectIntEQ(wolfSSL_X509_check_host(x509, altName, XSTRLEN(altName),
         WOLFSSL_MULTI_LABEL_WILDCARDS, NULL), WC_NO_ERR_TRACE(WOLFSSL_FAILURE));
 
+    /* chk of exactly chklen bytes with no terminator - every consumer must
+     * stay within the caller's declared length. */
+    {
+        char* bounded = (char*)XMALLOC(XSTRLEN(altName), NULL,
+                                       DYNAMIC_TYPE_TMP_BUFFER);
+        ExpectNotNull(bounded);
+        if (bounded != NULL) {
+            XMEMCPY(bounded, altName, XSTRLEN(altName));
+            ExpectIntEQ(X509_check_host(x509, bounded, XSTRLEN(altName), 0,
+                    NULL), WOLFSSL_SUCCESS);
+            XFREE(bounded, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+        }
+    }
+
     X509_free(x509);
 
     ExpectIntEQ(X509_check_host(NULL, altName, XSTRLEN(altName), 0, NULL),
diff --git a/wolfcrypt/src/ecc.c b/wolfcrypt/src/ecc.c
index c5ed6f6fd2c..48f66734cbd 100644
--- a/wolfcrypt/src/ecc.c
+++ b/wolfcrypt/src/ecc.c
@@ -9631,6 +9631,11 @@ static int ecc_verify_hash(mp_int *r, mp_int *s, const byte* hash,
         u1 = u1tmp;
         u2 = u2tmp;
     #endif
+       /* zeroed so the cleanup below no-ops if the init is skipped */
+       if (u1 != NULL)
+           XMEMSET(u1, 0, sizeof(mp_int));
+       if (u2 != NULL)
+           XMEMSET(u2, 0, sizeof(mp_int));
 #else
        u1 = e;
        u2 = w;
@@ -14090,18 +14095,23 @@ static int accel_fp_mul2add(int idx1, int idx2,
    int first;
 
 #ifdef WOLFSSL_SMALL_STACK
+   /* each is zeroed on acquisition so the cleanup below no-ops if a later
+    * allocation fails and the init is skipped */
    tka = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_ECC);
    if (tka == NULL) {
       err = MEMORY_E; goto done;
    }
+   XMEMSET(tka, 0, sizeof(mp_int));
    tkb = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_ECC);
    if (tkb == NULL) {
       err = MEMORY_E; goto done;
    }
+   XMEMSET(tkb, 0, sizeof(mp_int));
    order = (mp_int*)XMALLOC(sizeof(mp_int), NULL, DYNAMIC_TYPE_ECC);
    if (order == NULL) {
       err = MEMORY_E; goto done;
    }
+   XMEMSET(order, 0, sizeof(mp_int));
 #endif
 
    if (mp_init_multi(tka, tkb, order, NULL, NULL, NULL) != MP_OKAY) {
diff --git a/wolfcrypt/src/rsa.c b/wolfcrypt/src/rsa.c
index f5399560322..801fa037fb0 100644
--- a/wolfcrypt/src/rsa.c
+++ b/wolfcrypt/src/rsa.c
@@ -5461,6 +5461,7 @@ int wc_CheckProbablePrime_ex(const byte* pRaw, word32 pRawSz,
     }
     else
         ret = 0;
+
     if (ret == 0)
 #endif
         ret = mp_init_multi(p, q, e, NULL, NULL, NULL);
diff --git a/wolfcrypt/src/sakke.c b/wolfcrypt/src/sakke.c
index 28a2e01bf08..f98f376f690 100644
--- a/wolfcrypt/src/sakke.c
+++ b/wolfcrypt/src/sakke.c
@@ -2089,6 +2089,16 @@ static int sakke_accumulate_line_add_one(mp_proj* v, mp_int* prime, mp_digit mp,
     t3 = (mp_int *)XMALLOC(sizeof(*t3), NULL, DYNAMIC_TYPE_TMP_BUFFER);
     if (t3 == NULL)
         err = 1;
+
+    /* zeroed so the cleanup below no-ops if the init is skipped */
+    if (h != NULL)
+        XMEMSET(h, 0, sizeof(*h));
+    if (ty != NULL)
+        XMEMSET(ty, 0, sizeof(*ty));
+    if (tz != NULL)
+        XMEMSET(tz, 0, sizeof(*tz));
+    if (t3 != NULL)
+        XMEMSET(t3, 0, sizeof(*t3));
 #else
     mp_int tmp[4];
     mp_int* h = &tmp[0];
diff --git a/wolfcrypt/src/srp.c b/wolfcrypt/src/srp.c
index 3409dbec434..44c48d45ef0 100644
--- a/wolfcrypt/src/srp.c
+++ b/wolfcrypt/src/srp.c
@@ -617,6 +617,11 @@ int wc_SrpGetPublic(Srp* srp, byte* pub, word32* size)
             if (((i = (mp_int *)XMALLOC(sizeof(*i), srp->heap, DYNAMIC_TYPE_TMP_BUFFER)) == NULL) ||
                 ((j = (mp_int *)XMALLOC(sizeof(*j), srp->heap, DYNAMIC_TYPE_TMP_BUFFER)) == NULL))
                 r = MEMORY_E;
+            /* zeroed so the cleanup below no-ops if the init is skipped */
+            if (i != NULL)
+                XMEMSET(i, 0, sizeof(*i));
+            if (j != NULL)
+                XMEMSET(j, 0, sizeof(*j));
             if (!r)
 #endif
             {
@@ -762,6 +767,16 @@ int wc_SrpComputeKey(Srp* srp, byte* clientPubKey, word32 clientPubKeySz,
     temp1 = (mp_int *)XMALLOC(sizeof *temp1, srp->heap, DYNAMIC_TYPE_SRP);
     temp2 = (mp_int *)XMALLOC(sizeof *temp2, srp->heap, DYNAMIC_TYPE_SRP);
 
+    /* zeroed so the cleanup below no-ops if the init is skipped */
+    if (u != NULL)
+        XMEMSET(u, 0, sizeof *u);
+    if (s != NULL)
+        XMEMSET(s, 0, sizeof *s);
+    if (temp1 != NULL)
+        XMEMSET(temp1, 0, sizeof *temp1);
+    if (temp2 != NULL)
+        XMEMSET(temp2, 0, sizeof *temp2);
+
     if ((hash == NULL) ||
         (digest == NULL) ||
         (u == NULL) ||
diff --git a/wolfssl/internal.h b/wolfssl/internal.h
index dd20de7d6cb..7bfd1eb1d15 100644
--- a/wolfssl/internal.h
+++ b/wolfssl/internal.h
@@ -2335,7 +2335,8 @@ WOLFSSL_TEST_VIS int  MatchDomainName(const char* pattern, int len,
 WOLFSSL_LOCAL int  CheckForAltNames(DecodedCert* dCert, const char* domain,
                                     word32 domainLen, int* checkCN,
                                     unsigned int flags, byte isIP);
-WOLFSSL_LOCAL int  CheckIPAddr(DecodedCert* dCert, const char* ipasc);
+WOLFSSL_LOCAL int  CheckIPAddr(DecodedCert* dCert, const char* ipasc,
+                               size_t ipascLen);
 WOLFSSL_LOCAL void CopyDecodedName(WOLFSSL_X509_NAME* name, DecodedCert* dCert, int nameType);
 #endif
 WOLFSSL_LOCAL int  SetupTicket(WOLFSSL* ssl);
diff --git a/wolfssl/wolfcrypt/settings.h b/wolfssl/wolfcrypt/settings.h
index 461a2f3e839..bdd5018a418 100644
--- a/wolfssl/wolfcrypt/settings.h
+++ b/wolfssl/wolfcrypt/settings.h
@@ -407,6 +407,20 @@
     #define WOLF_CRYPT_FIPS_H
 #endif
 
+/* A configure-generated options.h is sometimes copied in as user_settings.h to
+ * seed a Windows build, carrying the POSIX host's header probes with it. Drop
+ * the ones naming a header the target lacks: MinGW ships <sys/time.h> (so only
+ * MSVC drops it) but not <sys/un.h> (so all of Windows does).
+ * WOLFSSL_KEEP_HOST_HEADER_PROBES skips this. */
+#ifndef WOLFSSL_KEEP_HOST_HEADER_PROBES
+    #ifdef _MSC_VER
+        #undef HAVE_SYS_TIME_H
+    #endif
+    #ifdef _WIN32
+        #undef HAVE_SYS_UN_H
+    #endif
+#endif
+
 /* Microsoft's ARM64 compiler defines _M_ARM64 but not __aarch64__.  The wolfSSL
  * ARMv8 assembly (WOLFSSL_ARMASM) and all of its C callers are gated on
  * __aarch64__, so map _M_ARM64 across when building that assembly with MSVC and