diff --git a/.Rbuildignore b/.Rbuildignore
index 8989c62f..9f149758 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -24,3 +24,6 @@
 ^\.jules(/.*)?$
 ^\.trivyignore\.yaml$
 ^trivy\.yaml$
+^test_dummy\.R$
+^test_validation\.R$
+^\.semgrepignore$
diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index a8207a48..769fb933 100644
--- a/.jules/sentinel.md
+++ b/.jules/sentinel.md
@@ -2,3 +2,8 @@
 **Vulnerability:** Unvalidated inputs passed to `if()` statements can cause process crashes (`condition has length > 1`) or unexpected coercion vulnerabilities.
 **Learning:** In R, optional boolean parameters that default to `NULL` should be validated using explicit runtime type validation (e.g., `if (!is.null(flag) && (!is.logical(flag) || length(flag) != 1 || is.na(flag)))`).
 **Prevention:** Always implement explicit runtime type validation for optional boolean parameters.
+
+## 2024-07-26 - 정수 오버플로우 강제 변환 취약점 수정
+**Vulnerability:** 대화형 `readline()` 입력에서 숫자 옵션을 검증할 때 제한 없는 숫자 클래스(예: `^[0-9]+$`)를 사용하면, 너무 큰 숫자가 정규표현식 검사를 통과한 후 `as.integer()`에서 `NA`로 평가되어 후속 프로세스 충돌을 유발할 수 있습니다.
+**Learning:** R 스크립트에서 대화형 `readline()` 숫자 입력을 검증할 때, 제한 없는 숫자 클래스보다 정확히 예상되는 값(예: `^[12]$`)과 엄격하게 일치시켜야 합니다.
+**Prevention:** 정수 오버플로우 강제 변환 취약점을 방지하기 위해 대화형 세션에서 예상되는 숫자 입력 옵션에 대해 항상 정밀한 정규표현식 매칭을 사용해야 합니다.
diff --git a/DESCRIPTION b/DESCRIPTION
index f31d3e1a..c90753c5 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -10,7 +10,7 @@ Description: Automates fixed item parameter linking for test linking under
     the item response theory paradigm using mirt package estimates.
 License: GPL-3 | file LICENSE
 Imports: mirt, methods
-Suggests: testthat (>= 3.0.0)
+Suggests: testthat (>= 3.0.0), mockery
 Encoding: UTF-8
 Config/testthat/edition: 3
 Config/roxygen2/version: 8.0.0
diff --git a/R/aFIPC.R b/R/aFIPC.R
index 62546519..918e19b1 100644
--- a/R/aFIPC.R
+++ b/R/aFIPC.R
@@ -141,7 +141,7 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", n)) {
+        if (grepl("^[12]$", n)) {
           return(as.integer(n))
         }
       }
@@ -171,7 +171,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for oldform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
@@ -390,7 +390,7 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for newform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
diff --git a/tests/testthat/test-sentinel-validation.R b/tests/testthat/test-sentinel-validation.R
index 900f0ee3..bb794566 100644
--- a/tests/testthat/test-sentinel-validation.R
+++ b/tests/testthat/test-sentinel-validation.R
@@ -35,3 +35,64 @@ test_that("autoFIPC validates boolean flags for newformBILOGprior, oldformBILOGp
     "Security Error: confirmCommonItems must be a single non-NA logical value or NULL"
   )
 })
+
+test_that("autoFIPC integer overflow coercion vulnerability in readline inputs is handled safely", {
+  # We test the interactive prompt paths by mocking readline to simulate bad inputs.
+
+  # For confirmCommonItems prompt
+  mock_readline_confirm <- mockery::mock("3", "9999999999", "invalid", cycle = TRUE)
+  mockery::stub(aFIPC::autoFIPC, 'readline', mock_readline_confirm)
+  mockery::stub(aFIPC::autoFIPC, 'interactive', function() TRUE)
+
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = data.frame(A=1),
+      oldformYData = data.frame(A=2),
+      newformCommonItemNames = c('A'),
+      oldformCommonItemNames = c('A')
+    ),
+    "Too many invalid common item confirmation attempts"
+  )
+})
+
+test_that("autoFIPC input validation for required arguments", {
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = 1, # Invalid type
+      oldformYData = data.frame(A=2),
+      newformCommonItemNames = c('A'),
+      oldformCommonItemNames = c('A')
+    ),
+    "Security Error: newformXData must be a data.frame, matrix, or a valid fitted mirt model"
+  )
+
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = data.frame(A=1),
+      oldformYData = 2, # Invalid type
+      newformCommonItemNames = c('A'),
+      oldformCommonItemNames = c('A')
+    ),
+    "Security Error: oldformYData must be a data.frame, matrix, or a valid fitted mirt model"
+  )
+
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = data.frame(A=1),
+      oldformYData = data.frame(A=2),
+      newformCommonItemNames = 1, # Invalid type
+      oldformCommonItemNames = c('A')
+    ),
+    "Security Error: newformCommonItemNames must be a character vector"
+  )
+
+  expect_error(
+    aFIPC::autoFIPC(
+      newformXData = data.frame(A=1),
+      oldformYData = data.frame(A=2),
+      newformCommonItemNames = c('A'),
+      oldformCommonItemNames = 2 # Invalid type
+    ),
+    "Security Error: oldformCommonItemNames must be a character vector"
+  )
+})