diff --git a/.Rbuildignore b/.Rbuildignore
index 232504f..28b2d85 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -22,3 +22,6 @@
 ^\.jules(/.*)?$
 ^\.trivyignore\.yaml$
 ^trivy\.yaml$
+^\.semgrepignore$
+^test_dummy\.R$
+^test_validation\.R$
diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index a8207a4..6b60ea2 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.
+
+## 2024-07-30 - Fix weak regex validation in readline prompts
+**Vulnerability:** Interactive `readline` prompts in `R/aFIPC.R` previously validated integer inputs using the weak regex `^[0-9]+$`. This allows arbitrarily large numbers which, when cast via `as.integer()`, cause integer overflow and coerce to `NA`, leading to unhandled condition lengths and process crashes.
+**Learning:** Broad regex limits in interactive R prompts are insecure and can easily cause DoS via unexpected data coercion.
+**Prevention:** Always use strictly bounded exact-match regex like `^[12]$` when validating integer inputs expected to match small, specific sets of choices.
diff --git a/R/aFIPC.R b/R/aFIPC.R
index 6254651..e8abf3c 100644
--- a/R/aFIPC.R
+++ b/R/aFIPC.R
@@ -141,7 +141,10 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", n)) {
+        # 🛡️ Sentinel Security Context:
+        # Strictly bound input to exactly '1' or '2' to prevent integer overflow
+        # where large numbers coerce to NA and cause unhandled condition crashes.
+        if (grepl("^[12]$", n)) {
           return(as.integer(n))
         }
       }
@@ -171,7 +174,10 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for oldform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            # 🛡️ Sentinel Security Context:
+            # Strictly bound input to exactly '1' or '2' to prevent integer overflow
+            # where large numbers coerce to NA and cause unhandled condition crashes.
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }
@@ -390,7 +396,10 @@ autoFIPC <-
               readline(
                 prompt = "Do you want to use default BILOG-MG priors for newform Data? (1: Yes 2: No) : "
               )
-            if (grepl("^[0-9]+$", n)) {
+            # 🛡️ Sentinel Security Context:
+            # Strictly bound input to exactly '1' or '2' to prevent integer overflow
+            # where large numbers coerce to NA and cause unhandled condition crashes.
+            if (grepl("^[12]$", n)) {
               return(as.integer(n))
             }
           }