diff --git a/src/backend/database/routes/credential-deploy-routes.ts b/src/backend/database/routes/credential-deploy-routes.ts
index 534983f3..1ad1b8df 100644
--- a/src/backend/database/routes/credential-deploy-routes.ts
+++ b/src/backend/database/routes/credential-deploy-routes.ts
@@ -87,6 +87,10 @@ async function deploySSHKeyToHost(
             }
 
             const keyPattern = keyParts[1];
+            if (!/^[A-Za-z0-9+/]+={0,2}$/.test(keyPattern)) {
+              clearTimeout(checkTimeout);
+              return rejectCheck(new Error("Invalid public key data"));
+            }
 
             conn.exec(
               `if [ -f ~/.ssh/authorized_keys ]; then grep -F "${keyPattern}" ~/.ssh/authorized_keys >/dev/null 2>&1; echo $?; else echo 1; fi`,
@@ -192,6 +196,10 @@ async function deploySSHKeyToHost(
             }
 
             const keyPattern = keyParts[1];
+            if (!/^[A-Za-z0-9+/]+={0,2}$/.test(keyPattern)) {
+              clearTimeout(verifyTimeout);
+              return rejectVerify(new Error("Invalid public key data"));
+            }
             conn.exec(
               `grep -F "${keyPattern}" ~/.ssh/authorized_keys >/dev/null 2>&1; echo $?`,
               (err, stream) => {