diff --git a/pe.c b/pe.c
index 5a486de..b188395 100644
--- a/pe.c
+++ b/pe.c
@@ -163,8 +163,10 @@ static ASN1_OBJECT *pe_spc_image_data_get(u_char **p, int *plen, FILE_FORMAT_CTX
         if (EVP_MD_size(ctx->options->md) > EVP_MD_size(EVP_sha1()))
             phtype = NID_sha256;
         link = pe_page_hash_link_get(ctx, phtype);
-        if (!link)
+        if (!link) {
+            SpcPeImageData_free(pid);
             return NULL; /* FAILED */
+        }
         pid->file = link;
     } else {
         pid->file = spc_link_obsolete_get();
@@ -404,6 +406,7 @@ static PKCS7 *pe_pkcs7_signature_new(FILE_FORMAT_CTX *ctx, BIO *hash)
     content = spc_indirect_data_content_get(hash, ctx);
     if (!content) {
         fprintf(stderr, "Failed to get spcIndirectDataContent\n");
+        PKCS7_free(p7);
         return NULL; /* FAILED */
     }
     if (!sign_spc_indirect_data_content(p7, content)) {
@@ -1044,7 +1047,7 @@ static u_char *pe_page_hash_calc(int *rphlen, FILE_FORMAT_CTX *ctx, int phtype)
         return NULL;  /* FAILED */
     }
     off = ctx->pe_ctx->header_size + 160 + (size_t)ctx->pe_ctx->pe32plus * 16;
-    if (hdrsize < off) {
+    if (hdrsize < off || hdrsize > filebound) {
         BIO_free_all(bhash);
         return NULL;  /* FAILED: header too small */
     }
@@ -1321,7 +1324,8 @@ static int pe_check_file(FILE_FORMAT_CTX *ctx)
 {
     uint32_t real_pe_checksum, sum = 0;
 
-    if (!ctx) {
+    if (ctx == NULL || ctx->pe_ctx == NULL || ctx->options == NULL
+        || ctx->options->indata == NULL) {
         fprintf(stderr, "Init error\n");
         return 0; /* FAILED */
     }
@@ -1333,25 +1337,52 @@ static int pe_check_file(FILE_FORMAT_CTX *ctx)
         printf("Calculated PE checksum: %08X\n", real_pe_checksum);
         printf("Warning: invalid PE checksum\n");
     }
+    /* Signature directory bounds */
     if (ctx->pe_ctx->sigpos == 0 || ctx->pe_ctx->siglen == 0
-        || ctx->pe_ctx->sigpos > ctx->pe_ctx->fileend) {
+        || ctx->pe_ctx->sigpos > ctx->pe_ctx->fileend
+        || ctx->pe_ctx->siglen > ctx->pe_ctx->fileend - ctx->pe_ctx->sigpos) {
         fprintf(stderr, "No signature found\n");
         return 0; /* FAILED */
     }
     /*
+     * Validate WIN_CERTIFICATE chain.
      * If the sum of the rounded dwLength values does not equal the Size value,
      * then either the attribute certificate table or the Size field is corrupted.
      */
     while (sum < ctx->pe_ctx->siglen) {
-        uint32_t len = GET_UINT32_LE(ctx->options->indata + ctx->pe_ctx->sigpos + sum);
-        if (ctx->pe_ctx->siglen - len > 8) {
+        uint32_t len, off;
+
+        /* Prevent overflow in sigpos + sum */
+        if (sum > UINT32_MAX - ctx->pe_ctx->sigpos) {
             fprintf(stderr, "Corrupted attribute certificate table\n");
-            fprintf(stderr, "Attribute certificate table size  : %08X\n", ctx->pe_ctx->siglen);
-            fprintf(stderr, "Attribute certificate entry length: %08X\n\n", len);
             return 0; /* FAILED */
         }
-        /* quadword align data */
-        len += len % 8 ? 8 - len % 8 : 0;
+        off = ctx->pe_ctx->sigpos + sum;
+
+        /* Need at least 4 bytes to read dwLength */
+        if (off > ctx->pe_ctx->fileend || ctx->pe_ctx->fileend - off < 4) {
+            fprintf(stderr, "Corrupted attribute certificate table\n");
+            return 0; /* FAILED */
+        }
+        len = GET_UINT32_LE(ctx->options->indata + off);
+
+        /* dwLength must include the 8-byte WIN_CERTIFICATE header */
+        if (len < 8 || len > ctx->pe_ctx->siglen - sum || len > ctx->pe_ctx->fileend - off) {
+            fprintf(stderr, "Corrupted attribute certificate table\n");
+            return 0; /* FAILED */
+        }
+
+        /* Quadword align data */
+        if (len % 8) {
+            uint32_t pad = 8 - (len % 8);
+
+            /* Ensure quadword alignment does not overflow or exceed remaining table size */
+            if (pad > ctx->pe_ctx->siglen - sum - len) {
+                fprintf(stderr, "Corrupted attribute certificate table\n");
+                return 0; /* FAILED */
+            }
+            len += pad;
+        }
         sum += len;
     }
     if (sum != ctx->pe_ctx->siglen) {