CVE-2026-45047

The apiHandler (and similarly webHandlerTelegramBot) processes user-provided JSON payloads by directly using json.NewDecoder(r.Body).Decode(&request) without restricting the maximum read size. An unauthenticated remote attacker can stream an extremely large, endless JSON payload (e.g., several Gigabytes of padding) over a single TCP connection. Because Go's JSON decoder attempts to allocate memory for the entire parsed structure, this rapidly exhausts the host's physical RAM or container limits, leading to an unrecoverable fatal error: runtime: out of memory.

This causes the Linux OOM Killer to instantly terminate the entire bird-lg-go daemon, resulting in a severe Remote Denial of Service (RDoS).

Details

In api.go:

func apiHandler(w http.ResponseWriter, r *http.Request) {
    var request apiRequest
    // VULNERABILITY: No http.MaxBytesReader protection before JSON decode
    err := json.NewDecoder(r.Body).Decode(&request) 
    // ...

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-45047 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260507060110-0ff87024cb9e); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-45047? CVE-2026-45047 is a high-severity uncontrolled resource consumption vulnerability in github.com/xddxdd/bird-lg-go (go), affecting versions < 0.0.0-20260507060110-0ff87024cb9e. It is fixed in 0.0.0-20260507060110-0ff87024cb9e. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2026-45047? CVE-2026-45047 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/xddxdd/bird-lg-go are affected by CVE-2026-45047? github.com/xddxdd/bird-lg-go (go) versions < 0.0.0-20260507060110-0ff87024cb9e is affected.
4. Is there a fix for CVE-2026-45047? Yes. CVE-2026-45047 is fixed in 0.0.0-20260507060110-0ff87024cb9e. Upgrade to this version or later.
5. Is CVE-2026-45047 exploitable, and should I be worried? Whether CVE-2026-45047 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-45047 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-45047? Upgrade github.com/xddxdd/bird-lg-go to 0.0.0-20260507060110-0ff87024cb9e or later.