diff --git a/.Rbuildignore b/.Rbuildignore
index 232504f..498d3ac 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -22,3 +22,19 @@
 ^\.jules(/.*)?$
 ^\.trivyignore\.yaml$
 ^trivy\.yaml$
+^test_.*\.R$
+^\.semgrepignore$
+^packrat/
+^\.git/
+^\..*Rcheck/
+^actionlint
+^gitleaks
+^.*\.tar\.gz$
+^.*_checksums\.txt$
+^AGENTS\.md$
+^ARCHITECTURE\.md$
+^CLAUDE\.md$
+^CONTRIBUTING\.md$
+^aFIPC\.Rproj$
+^docs/
+^trivy\.yaml$
diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index a8207a4..b6d1dee 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.
+
+## 2024-07-19 - Strict input validation for numeric interactive prompts
+**Vulnerability:** Interactive `readline()` prompts using unconstrained numeric regex matching (e.g., `^[0-9]+$`) can accept excessively large numbers (like `'9999999999999999999'`). When these strings are coerced using `as.integer()`, they can evaluate to `NA`, leading to integer overflow coercion vulnerabilities and downstream process crashes.
+**Learning:** In R, input validation regex for expected numeric inputs should explicitly match the exact expected values rather than generic digit classes.
+**Prevention:** When validating interactive `readline()` numeric inputs, strictly match against exact expected values (e.g., `^[12]$`) instead of unbounded digit classes (e.g., `^[0-9]+$`).
diff --git a/R/aFIPC.R b/R/aFIPC.R
index 6254651..918e19b 100644
--- a/R/aFIPC.R
+++ b/R/aFIPC.R
@@ -141,7 +141,7 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", 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))
             }
           }