diff -ruN a/NEWS b/NEWS
--- a/NEWS	2020-02-01 20:52:50.000000000 +0900
+++ b/NEWS	2021-04-16 08:56:18.255582011 +0900
@@ -149,6 +149,10 @@
   addresses for loaded libraries and thus bypass ASLR for a setuid
   program.  Reported by Marcin Kościelnicki.
 
+  CVE-2020-27618: An infinite loop has been fixed in the iconv program when
+  invoked with input containing redundant shift sequences in the IBM1364,
+  IBM1371, IBM1388, IBM1390, or IBM1399 character sets.
+
 The following bugs are resolved with this release:
 
   [12031] localedata: iconv -t ascii//translit with Greek characters
diff -ruN a/iconvdata/ibm1364.c b/iconvdata/ibm1364.c
--- a/iconvdata/ibm1364.c	2020-02-01 20:52:50.000000000 +0900
+++ b/iconvdata/ibm1364.c	2021-04-16 09:01:27.268590024 +0900
@@ -158,24 +158,14 @@
 									      \
     if (__builtin_expect (ch, 0) == SO)					      \
       {									      \
-	/* Shift OUT, change to DBCS converter.  */			      \
-	if (curcs == db)						      \
-	  {								      \
-	    result = __GCONV_ILLEGAL_INPUT;				      \
-	    break;							      \
-	  }								      \
+	/* Shift OUT, change to DBCS converter (redundant escape okay). */    \
 	curcs = db;							      \
 	++inptr;							      \
 	continue;							      \
       }									      \
     if (__builtin_expect (ch, 0) == SI)					      \
       {									      \
-	/* Shift IN, change to SBCS converter.  */			      \
-	if (curcs == sb)						      \
-	  {								      \
-	    result = __GCONV_ILLEGAL_INPUT;				      \
-	    break;							      \
-	  }								      \
+	/* Shift IN, change to SBCS converter (redundant escape okay).  */    \
 	curcs = sb;							      \
 	++inptr;							      \
 	continue;							      \