diff --git a/CHANGELOG.md b/CHANGELOG.md
index df2ffb8..b6aa1a2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -100,6 +100,7 @@
   index_size.
 * 'infe' boxes with an item_type different from 'mime' and without a
   null-terminated item_name are now considered invalid as per ISO/IEC 14496-12.
+* Fix missing header size check (b/335555272).
 
 ## [1.0.4] - 2024-02-08
 
diff --git a/src/read.c b/src/read.c
index d7c2b60..5e6b73c 100644
--- a/src/read.c
+++ b/src/read.c
@@ -4105,6 +4105,7 @@
         // Either there is no brand requiring anything in the file but a FileTypebox (so not AVIF), or it is invalid.
         return AVIF_FALSE;
     }
+    AVIF_CHECK(avifROStreamHasBytesLeft(&s, header.size));
 
     avifFileType ftyp;
     memset(&ftyp, 0, sizeof(avifFileType));