diff --git a/icu4c/source/common/ubidi.c b/icu4c/source/common/ubidi.c
index f17d5f1a9eb..b62b7df9081 100644
--- a/icu4c/source/common/ubidi.c
+++ b/icu4c/source/common/ubidi.c
@@ -679,10 +679,10 @@ bracketInit(UBiDi *pBiDi, BracketData *bd) {
     bd->isoRuns[0].contextPos=0;
     if(pBiDi->openingsMemory) {
         bd->openings=pBiDi->openingsMemory;
-        bd->openingsSize=pBiDi->openingsSize;
+        bd->openingsCount=pBiDi->openingsSize / sizeof(Opening);
     } else {
         bd->openings=bd->simpleOpenings;
-        bd->openingsSize=SIMPLE_OPENINGS_SIZE;
+        bd->openingsCount=SIMPLE_OPENINGS_SIZE;
     }
     bd->isNumbersSpecial=bd->pBiDi->reorderingMode==UBIDI_REORDER_NUMBERS_SPECIAL ||
                          bd->pBiDi->reorderingMode==UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL;
@@ -743,7 +743,7 @@ static UBool                            /* return TRUE if success */
 bracketAddOpening(BracketData *bd, UChar match, int32_t position) {
     IsoRun *pLastIsoRun=&bd->isoRuns[bd->isoRunLast];
     Opening *pOpening;
-    if(pLastIsoRun->limit>=bd->openingsSize) {  /* no available new entry */
+    if(pLastIsoRun->limit>=bd->openingsCount) {  /* no available new entry */
         UBiDi *pBiDi=bd->pBiDi;
         if(!getInitialOpeningsMemory(pBiDi, pLastIsoRun->limit * 2))
             return FALSE;
@@ -751,7 +751,7 @@ bracketAddOpening(BracketData *bd, UChar match, int32_t position) {
             uprv_memcpy(pBiDi->openingsMemory, bd->simpleOpenings,
                         SIMPLE_OPENINGS_SIZE * sizeof(Opening));
         bd->openings=pBiDi->openingsMemory;     /* may have changed */
-        bd->openingsSize=pBiDi->openingsSize;
+        bd->openingsCount=pBiDi->openingsSize / sizeof(Opening);
     }
     pOpening=&bd->openings[pLastIsoRun->limit];
     pOpening->position=position;
diff --git a/icu4c/source/common/ubidiimp.h b/icu4c/source/common/ubidiimp.h
index 21a7d5e265b..6db5b44c17a 100644
--- a/icu4c/source/common/ubidiimp.h
+++ b/icu4c/source/common/ubidiimp.h
@@ -173,7 +173,7 @@ typedef struct BracketData {
     /* array of opening entries which should be enough in most cases; no malloc() */
     Opening simpleOpenings[SIMPLE_OPENINGS_SIZE];
     Opening *openings;                  /* pointer to current array of entries */
-    int32_t openingsSize;               /* number of allocated entries */
+    int32_t openingsCount;              /* number of allocated entries */
     int32_t isoRunLast;                 /* index of last used entry */
     /* array of nested isolated sequence entries; can never excess UBIDI_MAX_EXPLICIT_LEVEL
        + 1 for index 0, + 1 for before the first isolated sequence */
diff --git a/icu4c/source/test/cintltst/cbiditst.c b/icu4c/source/test/cintltst/cbiditst.c
index c6252360c70..b1d1ede56c4 100644
--- a/icu4c/source/test/cintltst/cbiditst.c
+++ b/icu4c/source/test/cintltst/cbiditst.c
@@ -87,6 +87,8 @@ static void testContext(void);
 
 static void doTailTest(void);
 
+static void testBracketOverflow(void);
+
 /* new BIDI API */
 static void testReorderingMode(void);
 static void testReorderRunsOnly(void);
@@ -133,6 +135,7 @@ addComplexTest(TestNode** root) {
     addTest(root, testClassOverride, "complex/bidi/TestClassOverride");
     addTest(root, testGetBaseDirection, "complex/bidi/testGetBaseDirection");
     addTest(root, testContext, "complex/bidi/testContext");
+    addTest(root, testBracketOverflow, "complex/bidi/TestBracketOverflow");
 
     addTest(root, doArabicShapingTest, "complex/arabic-shaping/ArabicShapingTest");
     addTest(root, doLamAlefSpecialVLTRArabicShapingTest, "complex/arabic-shaping/lamalef");
@@ -4896,3 +4899,25 @@ testContext(void) {
 
     log_verbose("\nExiting TestContext \n\n");
 }
+
+/* Ticket#11054 ubidi_setPara crash with heavily nested brackets */
+static void
+testBracketOverflow(void) {
+    static const char* TEXT = "(((((((((((((((((((((((((((((((((((((((((a)(A)))))))))))))))))))))))))))))))))))))))))";
+    UErrorCode status = U_ZERO_ERROR;
+    UBiDi* bidi;
+    UChar src[100];
+    UChar dest[100];
+    int32_t len;
+
+    bidi = ubidi_open();
+    len = uprv_strlen(TEXT);
+    pseudoToU16(len, TEXT, src);
+    ubidi_setPara(bidi, src, len, UBIDI_DEFAULT_LTR , NULL, &status);
+    if (U_FAILURE(status)) {
+        log_err("setPara failed with heavily nested brackets - %s", u_errorName(status));
+    }
+
+    ubidi_close(bidi);
+}
+