diff --git a/modules/objdetect/src/qrcode_encoder.cpp b/modules/objdetect/src/qrcode_encoder.cpp
index a58eb08f9e..a08951ad77 100644
--- a/modules/objdetect/src/qrcode_encoder.cpp
+++ b/modules/objdetect/src/qrcode_encoder.cpp
@@ -1359,11 +1359,11 @@ private:
     void extractCodewords(Mat& source, std::vector<uint8_t>& codewords);
     bool errorCorrection(std::vector<uint8_t>& codewords);
     bool errorCorrectionBlock(std::vector<uint8_t>& codewords);
-    void decodeSymbols(String& result);
+    bool decodeSymbols(String& result);
     void decodeNumeric(String& result);
-    void decodeAlpha(String& result);
+    bool decodeAlpha(String& result);
     void decodeByte(String& result);
-    void decodeECI(String& result);
+    bool decodeECI(String& result);
     void decodeKanji(String& result);
     void decodeStructuredAppend(String& result);
 };
@@ -1472,7 +1472,10 @@ bool QRCodeDecoderImpl::run(const Mat& straight, String& decoded_info) {
     if (!errorCorrection(bitstream.data)) {
         return false;
     }
-    decodeSymbols(decoded_info);
+    if (!decodeSymbols(decoded_info)) {
+        decoded_info = "";
+        return false;
+    }
     return true;
 }
 
@@ -1737,7 +1740,7 @@ void QRCodeDecoderImpl::extractCodewords(Mat& source, std::vector<uint8_t>& code
     }
 }
 
-void QRCodeDecoderImpl::decodeSymbols(String& result) {
+bool QRCodeDecoderImpl::decodeSymbols(String& result) {
     CV_Assert(!bitstream.empty());
 
     // Decode depends on the mode
@@ -1750,15 +1753,19 @@ void QRCodeDecoderImpl::decodeSymbols(String& result) {
         }
 
         if (currMode == 0 || bitstream.empty())
-            return;
+            return true;
         if (currMode == QRCodeEncoder::EncodeMode::MODE_NUMERIC)
             decodeNumeric(result);
-        else if (currMode == QRCodeEncoder::EncodeMode::MODE_ALPHANUMERIC)
-            decodeAlpha(result);
+        else if (currMode == QRCodeEncoder::EncodeMode::MODE_ALPHANUMERIC) {
+            if (!decodeAlpha(result))
+                return false;
+        }
         else if (currMode == QRCodeEncoder::EncodeMode::MODE_BYTE)
             decodeByte(result);
-        else if (currMode == QRCodeEncoder::EncodeMode::MODE_ECI)
-            decodeECI(result);
+        else if (currMode == QRCodeEncoder::EncodeMode::MODE_ECI) {
+            if (!decodeECI(result))
+                return false;
+        }
         else if (currMode == QRCodeEncoder::EncodeMode::MODE_KANJI)
             decodeKanji(result);
         else if (currMode == QRCodeEncoder::EncodeMode::MODE_STRUCTURED_APPEND) {
@@ -1769,6 +1776,7 @@ void QRCodeDecoderImpl::decodeSymbols(String& result) {
         else
             CV_Error(Error::StsNotImplemented, format("mode %d", currMode));
     }
+    return true;
 }
 
 void QRCodeDecoderImpl::decodeNumeric(String& result) {
@@ -1788,7 +1796,7 @@ void QRCodeDecoderImpl::decodeNumeric(String& result) {
     }
 }
 
-void QRCodeDecoderImpl::decodeAlpha(String& result) {
+bool QRCodeDecoderImpl::decodeAlpha(String& result) {
     static const char map[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                                'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
                                'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
@@ -1798,13 +1806,18 @@ void QRCodeDecoderImpl::decodeAlpha(String& result) {
     int num = bitstream.next(version <= 9 ? 9 : (version <= 26 ? 11 : 13));
     for (int i = 0; i < num / 2; ++i) {
         int tuple = bitstream.next(11);
+        if (tuple >= 45 * 45)
+            return false;
         result += map[tuple / 45];
         result += map[tuple % 45];
     }
     if (num % 2) {
         int value = bitstream.next(6);
+        if (value >= 45)
+            return false;
         result += map[value];
     }
+    return true;
 }
 
 void QRCodeDecoderImpl::decodeByte(String& result) {
@@ -1814,7 +1827,7 @@ void QRCodeDecoderImpl::decodeByte(String& result) {
     }
 }
 
-void QRCodeDecoderImpl::decodeECI(String& result) {
+bool QRCodeDecoderImpl::decodeECI(String& result) {
     int eciAssignValue = bitstream.next(8);
     for (int i = 0; i < 8; ++i) {
         if (eciAssignValue & 1 << (7 - i))
@@ -1825,8 +1838,7 @@ void QRCodeDecoderImpl::decodeECI(String& result) {
     if (this->eci == 0) {
         this->eci = static_cast<QRCodeEncoder::ECIEncodings>(eciAssignValue);
     }
-    decodeSymbols(result);
-
+    return decodeSymbols(result);
 }
 
 void QRCodeDecoderImpl::decodeKanji(String& result) {
diff --git a/modules/objdetect/test/test_qrcode.cpp b/modules/objdetect/test/test_qrcode.cpp
index c49480d38f..f6dfb14aa1 100644
--- a/modules/objdetect/test/test_qrcode.cpp
+++ b/modules/objdetect/test/test_qrcode.cpp
@@ -571,6 +571,54 @@ TEST(Objdetect_QRCode_decode, decode_regression_version_25)
     EXPECT_EQ(expect_msg, decoded_msg);
 }
 
+TEST(Objdetect_QRCode_decode, decode_alphanumeric_out_of_range)
+{
+    // Version 1 QR with a valid Reed-Solomon block whose alphanumeric segment
+    // carries an 11-bit pair value of 2047. decodeAlpha computes 2047 / 45 == 45
+    // and used to read map[45], one past the 45-entry table, leaking an adjacent
+    // byte into the decoded string. The decoder must reject it and return an
+    // empty string instead.
+    static const char* modules[21] = {
+        "000000011011010000000",
+        "011111010011010111110",
+        "010001011011010100010",
+        "010001010011010100010",
+        "010001011011010100010",
+        "011111010011010111110",
+        "000000010101010000000",
+        "111111111011011111111",
+        "000001000011001010101",
+        "111111101001011011000",
+        "000111010001011011000",
+        "001001100111011011000",
+        "000001011011011011000",
+        "111111110101011011000",
+        "000000010111011011001",
+        "011111011101011011001",
+        "010001010001011011011",
+        "010001010001011011011",
+        "010001010001011011011",
+        "011111010001011011010",
+        "000000010001011011011"
+    };
+    Mat qr(21, 21, CV_8UC1);
+    for (int i = 0; i < 21; i++)
+        for (int j = 0; j < 21; j++)
+            qr.at<uchar>(i, j) = modules[i][j] == '1' ? 255 : 0;
+
+    Mat src;
+    cv::resize(qr, src, qr.size() * 10, 0, 0, INTER_NEAREST);
+    cv::copyMakeBorder(src, src, 40, 40, 40, 40, BORDER_CONSTANT, Scalar(255));
+
+    QRCodeDetector qrcode;
+    std::vector<Point> corners;
+    ASSERT_TRUE(qrcode.detect(src, corners));
+    Mat straight_barcode;
+    std::string decoded_info;
+    EXPECT_NO_THROW(decoded_info = qrcode.decode(src, corners, straight_barcode));
+    EXPECT_TRUE(decoded_info.empty());
+}
+
 TEST_P(Objdetect_QRCode_detectAndDecodeMulti, decode_9_qrcodes_version7)
 {
     const std::string name_current_image = "9_qrcodes_version7.jpg";