From 7d4ad1cc2ac83509540a678f30a76caf127611ee Mon Sep 17 00:00:00 2001
From: metsw24-max <metsw24@gmail.com>
Date: Tue, 23 Jun 2026 17:29:03 +0530
Subject: [PATCH] reject non-finite numbers in is.number

---
 lib/is.mjs          |  2 +-
 test/unit/affine.js | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/is.mjs b/lib/is.mjs
index bfb4188f8..c3e201200 100644
--- a/lib/is.mjs
+++ b/lib/is.mjs
@@ -78,7 +78,7 @@ const string = (val) => typeof val === 'string' && val.length > 0;
  * Is this value a real number?
  * @private
  */
-const number = (val) => typeof val === 'number' && !Number.isNaN(val);
+const number = (val) => typeof val === 'number' && Number.isFinite(val);
 
 /**
  * Is this value an integer?
diff --git a/test/unit/affine.js b/test/unit/affine.js
index ab662f878..5ae477bf7 100644
--- a/test/unit/affine.js
+++ b/test/unit/affine.js
@@ -73,6 +73,20 @@ suite('Affine transform', () => {
           .affine([[4, 4], [4, 4]], { ody: 'invalid ody type' });
       });
     });
+    test('Non-finite idx offset', (t) => {
+      t.plan(1);
+      t.assert.throws(() => {
+        sharp(fixtures.inputJpg)
+          .affine([[4, 4], [4, 4]], { idx: Infinity });
+      });
+    });
+    test('Non-finite idy offset', (t) => {
+      t.plan(1);
+      t.assert.throws(() => {
+        sharp(fixtures.inputJpg)
+          .affine([[4, 4], [4, 4]], { idy: -Infinity });
+      });
+    });
     test('Invalid interpolator', (t) => {
       t.plan(1);
       t.assert.throws(() => {