diff --git a/src/lib/isRgbColor.js b/src/lib/isRgbColor.js
index e9fb60253..eb2a563ef 100644
--- a/src/lib/isRgbColor.js
+++ b/src/lib/isRgbColor.js
@@ -27,8 +27,11 @@ export default function isRgbColor(str, options) {
     if (!startsWithRgb.test(str)) {
       return false;
     }
-    // strip all whitespace
-    str = str.replace(/\s/g, '');
+    // collapse whitespace runs, then drop only the whitespace adjacent to the
+    // parentheses and commas; whitespace inside a channel/alpha/percent token is
+    // kept so malformed values such as 'rgb(2 55,0,0)' or 'rgb(25 %,0%,0%)' are
+    // still rejected. Two linear passes avoid polynomial backtracking (#2885)
+    str = str.replace(/\s+/g, ' ').replace(/ ?([(),]) ?/g, '$1');
   }
 
   if (!includePercentValues) {
diff --git a/test/validators.test.js b/test/validators.test.js
index 98d2a12ff..cd9eb9156 100644
--- a/test/validators.test.js
+++ b/test/validators.test.js
@@ -5309,11 +5309,15 @@ describe('Validators', () => {
         'rgba(255, 255, 255, 0.1)',
         'rgb(5% ,5% ,5%)',
         'rgba(5%,5%,5%, .3)',
+        'rgb( 255 , 0 , 0 )',
       ],
       invalid: [
         'r         g    b(   0,         251,       222     )',
         'rgb(4,4,5%)',
         'rgb(101%,101%,101%)',
+        'rgb(2 55,0,0)',
+        'rgba(0,0,0,0. 5)',
+        'rgb(25 %,0%,0%)',
 
       ],
     });