From 52c74b563ef6ddf15903c2257c05b2b835dbe87c Mon Sep 17 00:00:00 2001
From: Brian Popow <popow@gmx.de>
Date: Tue, 10 Mar 2026 17:22:09 +0100
Subject: [PATCH] Add check, if translatedKeywordLength is < 0

---
 src/ImageSharp/Formats/Png/PngDecoderCore.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/ImageSharp/Formats/Png/PngDecoderCore.cs b/src/ImageSharp/Formats/Png/PngDecoderCore.cs
index eadd2a43ce..bca682d77a 100644
--- a/src/ImageSharp/Formats/Png/PngDecoderCore.cs
+++ b/src/ImageSharp/Formats/Png/PngDecoderCore.cs
@@ -1966,6 +1966,11 @@ internal sealed class PngDecoderCore : ImageDecoderCore
 
         int translatedKeywordStartIdx = langStartIdx + languageLength + 1;
         int translatedKeywordLength = data[translatedKeywordStartIdx..].IndexOf((byte)0);
+        if (translatedKeywordLength < 0)
+        {
+            return;
+        }
+
         string translatedKeyword = PngConstants.TranslatedEncoding.GetString(data.Slice(translatedKeywordStartIdx, translatedKeywordLength));
 
         ReadOnlySpan<byte> keywordBytes = data[..zeroIndexKeyword];