diff -rupN poppler-0.67.0/poppler/XRef.cc poppler-0.67.0-new/poppler/XRef.cc
--- poppler-0.67.0/poppler/XRef.cc 2019-02-20 19:27:38.529686101 +0100
+++ poppler-0.67.0-new/poppler/XRef.cc 2019-02-20 19:27:38.641686122 +0100
@@ -1628,6 +1628,11 @@ DummyXRefEntry dummyXRefEntry;
XRefEntry *XRef::getEntry(int i, GBool complainIfMissing)
{
+ if (unlikely(i < 0)) {
+ error(errInternal, -1, "Request for invalid XRef entry [{0:d}]", i);
+ return &dummyXRefEntry;
+ }
+
if (i >= size || entries[i].type == xrefEntryNone) {
if ((!xRefStream) && mainXRefEntriesOffset) {