diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
index 18dc3072b4..fa117ab63c 100644
--- a/src/journal/journal-file.c
+++ b/src/journal/journal-file.c
@@ -1572,6 +1572,9 @@ static int journal_file_append_field(
         assert(f);
         assert(field && size > 0);
 
+        if (!journal_field_valid(field, size, true))
+                return -EBADMSG;
+
         hash = journal_file_hash_data(f, field, size);
 
         r = journal_file_find_field_object_with_hash(f, field, size, hash, &o, &p);
diff --git a/test/fuzz/fuzz-journal-remote/oss-fuzz-25353 b/test/fuzz/fuzz-journal-remote/oss-fuzz-25353
new file mode 100644
index 0000000000..94e5fbb93e
Binary files /dev/null and b/test/fuzz/fuzz-journal-remote/oss-fuzz-25353 differ