diff --git a/third_party/lcms/src/cmsintrp.c b/third_party/lcms/src/cmsintrp.c
index 3d9a40530..22de3e550 100644
--- a/third_party/lcms/src/cmsintrp.c
+++ b/third_party/lcms/src/cmsintrp.c
@@ -200,8 +200,8 @@ void LinLerp1D(CMSREGISTER const cmsUInt16Number Value[],
     int val3;
     const cmsUInt16Number* LutTable = (cmsUInt16Number*) p ->Table;
 
-    // if last value...
-    if (Value[0] == 0xffff) {
+    // if last value or just one point
+    if (Value[0] == 0xffff || p->Domain[0] == 0) {
 
         Output[0] = LutTable[p -> Domain[0]];      
     }
@@ -240,7 +240,7 @@ void LinLerp1Dfloat(const cmsFloat32Number Value[],
        val2 = fclamp(Value[0]);
 
        // if last value...
-       if (val2 == 1.0) {
+       if (val2 == 1.0 || p->Domain[0] == 0) {
            Output[0] = LutTable[p -> Domain[0]];          
        }
        else
@@ -274,20 +274,34 @@ void Eval1Input(CMSREGISTER const cmsUInt16Number Input[],
        cmsUInt32Number OutChan;
        const cmsUInt16Number* LutTable = (cmsUInt16Number*) p16 -> Table;
 
-       v = Input[0] * p16 -> Domain[0];
-       fk = _cmsToFixedDomain(v);
 
-       k0 = FIXED_TO_INT(fk);
-       rk = (cmsUInt16Number) FIXED_REST_TO_INT(fk);
+       // if last value...
+       if (Input[0] == 0xffff || p16->Domain[0] == 0) {
+
+           cmsUInt16Number y0 = LutTable[p16->Domain[0]];
+
+           for (OutChan = 0; OutChan < p16->nOutputs; OutChan++) {
+               Output[OutChan] = y0;
+           }
+       }
+       else
+       {
+
+           v = Input[0] * p16->Domain[0];
+           fk = _cmsToFixedDomain(v);
+
+           k0 = FIXED_TO_INT(fk);
+           rk = (cmsUInt16Number)FIXED_REST_TO_INT(fk);
 
-       k1 = k0 + (Input[0] != 0xFFFFU ? 1 : 0);
+           k1 = k0 + (Input[0] != 0xFFFFU ? 1 : 0);
 
-       K0 = p16 -> opta[0] * k0;
-       K1 = p16 -> opta[0] * k1;
+           K0 = p16->opta[0] * k0;
+           K1 = p16->opta[0] * k1;
 
-       for (OutChan=0; OutChan < p16->nOutputs; OutChan++) {
+           for (OutChan = 0; OutChan < p16->nOutputs; OutChan++) {
 
-           Output[OutChan] = LinearInterp(rk, LutTable[K0+OutChan], LutTable[K1+OutChan]);
+               Output[OutChan] = LinearInterp(rk, LutTable[K0 + OutChan], LutTable[K1 + OutChan]);
+           }
        }
 }
 
@@ -308,7 +322,7 @@ void Eval1InputFloat(const cmsFloat32Number Value[],
     val2 = fclamp(Value[0]);
 
     // if last value...
-    if (val2 == 1.0) {
+    if (val2 == 1.0 || p->Domain[0] == 0) {
 
         y0 = LutTable[p->Domain[0]];
 
diff --git a/third_party/lcms/src/cmsio0.c b/third_party/lcms/src/cmsio0.c
index 743b958df..ff8c464fc 100644
--- a/third_party/lcms/src/cmsio0.c
+++ b/third_party/lcms/src/cmsio0.c
@@ -1538,8 +1538,12 @@ void* CMSEXPORT cmsReadTag(cmsHPROFILE hProfile, cmsTagSignature sig)
     if (!_cmsLockMutex(Icc->ContextID, Icc ->UsrMutex)) return NULL;
 
     n = _cmsSearchTag(Icc, sig, TRUE);
-    if (n < 0) goto Error;               // Not found, return NULL
-
+    if (n < 0)
+    {
+        // Not found, return NULL
+        _cmsUnlockMutex(Icc->ContextID, Icc->UsrMutex);
+        return NULL;
+    }
 
     // If the element is already in memory, return the pointer
     if (Icc -> TagPtrs[n]) {
diff --git a/third_party/lcms/src/cmstypes.c b/third_party/lcms/src/cmstypes.c
index 825b11eb1..49207735b 100644
--- a/third_party/lcms/src/cmstypes.c
+++ b/third_party/lcms/src/cmstypes.c
@@ -3515,42 +3515,48 @@ void *Type_UcrBg_Read(struct _cms_typehandler_struct* self, cmsIOHANDLER* io, cm
 {
     cmsUcrBg* n = (cmsUcrBg*) _cmsMallocZero(self ->ContextID, sizeof(cmsUcrBg));
     cmsUInt32Number CountUcr, CountBg;
+    cmsInt32Number SignedSizeOfTag = (cmsInt32Number)SizeOfTag;
     char* ASCIIString;
 
     *nItems = 0;
     if (n == NULL) return NULL;
 
     // First curve is Under color removal
+
+    if (SignedSizeOfTag < sizeof(cmsUInt32Number)) return NULL;    
     if (!_cmsReadUInt32Number(io, &CountUcr)) return NULL;
-    if (SizeOfTag < sizeof(cmsUInt32Number)) return NULL;
-    SizeOfTag -= sizeof(cmsUInt32Number);
+    SignedSizeOfTag -= sizeof(cmsUInt32Number);
 
     n ->Ucr = cmsBuildTabulatedToneCurve16(self ->ContextID, CountUcr, NULL);
     if (n ->Ucr == NULL) return NULL;
 
+    if (SignedSizeOfTag < (cmsInt32Number)CountUcr * sizeof(cmsUInt16Number)) return NULL;
     if (!_cmsReadUInt16Array(io, CountUcr, n ->Ucr->Table16)) return NULL;
-    if (SizeOfTag < sizeof(cmsUInt32Number)) return NULL;
-    SizeOfTag -= CountUcr * sizeof(cmsUInt16Number);
+  
+    SignedSizeOfTag -= CountUcr * sizeof(cmsUInt16Number);
 
     // Second curve is Black generation
+
+    if (SignedSizeOfTag < sizeof(cmsUInt32Number)) return NULL;    
     if (!_cmsReadUInt32Number(io, &CountBg)) return NULL;
-    if (SizeOfTag < sizeof(cmsUInt32Number)) return NULL;
-    SizeOfTag -= sizeof(cmsUInt32Number);
+    SignedSizeOfTag -= sizeof(cmsUInt32Number);
 
     n ->Bg = cmsBuildTabulatedToneCurve16(self ->ContextID, CountBg, NULL);
     if (n ->Bg == NULL) return NULL;
+
+    if (SignedSizeOfTag < (cmsInt32Number) CountBg * sizeof(cmsUInt16Number)) return NULL;    
     if (!_cmsReadUInt16Array(io, CountBg, n ->Bg->Table16)) return NULL;
-    if (SizeOfTag < CountBg * sizeof(cmsUInt16Number)) return NULL;
-    SizeOfTag -= CountBg * sizeof(cmsUInt16Number);
-    if (SizeOfTag == UINT_MAX) return NULL;
+    SignedSizeOfTag -= CountBg * sizeof(cmsUInt16Number);
+
+    if (SignedSizeOfTag < 0 || SignedSizeOfTag > 32000) return NULL;
 
     // Now comes the text. The length is specified by the tag size
     n ->Desc = cmsMLUalloc(self ->ContextID, 1);
     if (n ->Desc == NULL) return NULL;
 
-    ASCIIString = (char*) _cmsMalloc(self ->ContextID, SizeOfTag + 1);
-    if (io ->Read(io, ASCIIString, sizeof(char), SizeOfTag) != SizeOfTag) return NULL;
-    ASCIIString[SizeOfTag] = 0;
+    ASCIIString = (char*) _cmsMalloc(self ->ContextID, SignedSizeOfTag + 1);
+    if (io ->Read(io, ASCIIString, sizeof(char), SignedSizeOfTag) != (cmsUInt32Number) SignedSizeOfTag) return NULL;
+    ASCIIString[SignedSizeOfTag] = 0;
     cmsMLUsetASCII(n ->Desc, cmsNoLanguage, cmsNoCountry, ASCIIString);
     _cmsFree(self ->ContextID, ASCIIString);