diff --git a/.jules/sentinel.md b/.jules/sentinel.md
index a8207a4..d789709 100644
--- a/.jules/sentinel.md
+++ b/.jules/sentinel.md
@@ -1,4 +1,5 @@
-## 2024-07-12 - Fix missing parameter validations
-**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.
+## 2026-07-21 - Fix integer overflow coercion vulnerabilities in interactive prompts
+
+**Vulnerability:** Interactive prompts using `readline()` validated numeric inputs with `^[0-9]+$`, which allowed excessively large numeric strings to pass the regex check but evaluate to `NA` when coerced with `as.integer()`. This unhandled `NA` would cause process crashes when used in conditional statements.
+**Learning:** In R, unbounded numeric regex validation (`^[0-9]+$`) coupled with `as.integer()` coercion is insufficient for exact matching and can lead to unhandled integer overflow exceptions.
+**Prevention:** Strictly match interactive numeric inputs against exact expected values (e.g., `^[12]$`) instead of unbounded digit classes to prevent both unexpected values and integer overflow coercion vulnerabilities.
diff --git a/R/aFIPC.R b/R/aFIPC.R
index 6254651..918e19b 100644
--- a/R/aFIPC.R
+++ b/R/aFIPC.R
@@ -141,7 +141,7 @@ autoFIPC <-
       }
       for (attempt in seq_len(3)) {
         n <- readline(prompt = "Is it correct? (1: Yes 2: No) : ")
-        if (grepl("^[0-9]+$", 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))
             }
           }