diff --git a/third_party/libopenjpeg20/t1.c b/third_party/libopenjpeg20/t1.c
index 1ad850c77..d290c38d5 100644
--- a/third_party/libopenjpeg20/t1.c
+++ b/third_party/libopenjpeg20/t1.c
@@ -1387,6 +1387,9 @@ static OPJ_BOOL opj_t1_decode_cblk(opj_t1_t *t1,
        }
 
        bpno_plus_one = (OPJ_INT32)(roishift + cblk->numbps);
+    if (bpno_plus_one > 30) {
+        return OPJ_FALSE;
+    }
        passtype = 2;
 
        opj_mqc_resetstates(mqc);