diff --git a/third_party/lcms2-2.6/0015-sanitize-float-read.patch b/third_party/lcms2-2.6/0015-sanitize-float-read.patch
new file mode 100644
index 0000000..70dc7b3
--- /dev/null
+++ b/third_party/lcms2-2.6/0015-sanitize-float-read.patch
@@ -0,0 +1,15 @@
+diff --git a/third_party/lcms2-2.6/src/cmsplugin.c b/third_party/lcms2-2.6/src/cmsplugin.c
+index b95befb..4ba998b 100644
+--- a/third_party/lcms2-2.6/src/cmsplugin.c
++++ b/third_party/lcms2-2.6/src/cmsplugin.c
+@@ -182,7 +182,9 @@ cmsBool CMSEXPORT  _cmsReadFloat32Number(cmsIOHANDLER* io, cmsFloat32Number* n)
+         if (isnan(*n))
+             return FALSE;
+     }
+-    return TRUE;
++
++    // fpclassify() required by C99
++    return (fpclassify(*n) == FP_ZERO) || (fpclassify(*n) == FP_NORMAL);
+ }
+ 
+ 
diff --git a/third_party/lcms2-2.6/README.pdfium b/third_party/lcms2-2.6/README.pdfium
index 075d2e0..c775609 100644
--- a/third_party/lcms2-2.6/README.pdfium
+++ b/third_party/lcms2-2.6/README.pdfium
@@ -25,4 +25,6 @@
     https://github.com/mm2/Little-CMS/commit/c0a98d86
 0013-utf8.patch: Encode source files as utf-8.
 0014-avoid-fixed-inf.patch: Avoid fixed number LUT optimization on inf values.
+0015-sanitize-float-read.patch: Sanitize floating point read. Partially backport
+    from upstream https://github.com/mm2/Little-CMS/commit/4011a6e3
 TODO(ochang): List other patches.
diff --git a/third_party/lcms2-2.6/src/cmsplugin.c b/third_party/lcms2-2.6/src/cmsplugin.c
index b95befb..42c4002 100644
--- a/third_party/lcms2-2.6/src/cmsplugin.c
+++ b/third_party/lcms2-2.6/src/cmsplugin.c
@@ -182,7 +182,9 @@
         if (isnan(*n))
             return FALSE;
     }
-    return TRUE;
+
+    // fpclassify() required by C99
+    return (fpclassify(*n) == FP_ZERO) || (fpclassify(*n) == FP_NORMAL);
 }