Overview
The CVE-2026-7555 record describes a remote SQL injection in itsourcecode Electronic Judging System 1.0, triggered by manipulating the Username parameter in /intrams/login.php. An attacker could alter the query logic and bypass authentication or disclose data, with a publicly available exploit increasing the real-world risk.
In this Go (Gin) remediation guide, we map this class of vulnerability to Go code. The issue arises when user input is directly embedded in SQL statements (CWE-89) or when the query is constructed with unsafe string concatenation (CWE-74 association in the CVE). The fix is to stop interpolating untrusted data into SQL and instead use parameterized queries or prepared statements so the database driver treats inputs as data, not code.
In a Gin-based Go application, the same vulnerability pattern occurs if you build queries via string formatting or concatenation with request data. The safe pattern uses placeholders and bound parameters (or an ORM that uses parameterization) along with input validation and principle of least privilege for the database user. The sample code below shows a vulnerable endpoint followed by a secure alternative and demonstrates how to apply these practices in real-world Go code.
Affected Versions
1.0 (itsourcecode Electronic Judging System)
Code Fix Example
Go (Gin) API Security Remediation
package main
import (
"database/sql"
"fmt"
"log"
"net/http"
"github.com/gin-gonic/gin"
_ "github.com/mattn/go-sqlite3"
)
func setupDB() *sql.DB {
db, err := sql.Open("sqlite3", ":memory:")
if err != nil {
log.Fatal(err)
}
_, err = db.Exec(`CREATE TABLE users (id INTEGER PRIMARY KEY, username TEXT, password TEXT)`)
if err != nil {
log.Fatal(err)
}
_, err = db.Exec(`INSERT INTO users (username, password) VALUES ('alice','password123'), ('bob','hunter2')`)
if err != nil {
log.Fatal(err)
}
return db
}
func main() {
db := setupDB()
defer db.Close()
r := gin.Default()
// Vulnerable endpoint: demonstrates unsafe string interpolation with user input
// This mirrors the type of vulnerability described in CVE-2026-7555
r.POST("/login-vulnerable", func(c *gin.Context) {
username := c.PostForm("username")
password := c.PostForm("password")
// Vulnerable query construction (unsafe): wide open to SQL injection
query := fmt.Sprintf("SELECT id FROM users WHERE username='%s' AND password='%s'", username, password)
var id int
err := db.QueryRow(query).Scan(&id)
if err != nil {
c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
return
}
c.JSON(http.StatusOK, gin.H{"status": "ok", "user_id": id})
})
// Fixed endpoint: uses parameterized queries and bound parameters
r.POST("/login-fixed", func(c *gin.Context) {
username := c.PostForm("username")
password := c.PostForm("password")
var id int
// Safe: parameterized query with placeholders
err := db.QueryRow("SELECT id FROM users WHERE username = ? AND password = ?", username, password).Scan(&id)
if err != nil {
c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
return
}
c.JSON(http.StatusOK, gin.H{"status": "ok", "user_id": id})
})
r.Run(":8080")
}