PT-2026-39903 · Go · Github.Com/Xddxdd/Bird-Lg-Go

Published 2026-05-11 · Updated 2026-05-11 · CVE-2026-45047

OSV

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

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) 
  // ...

Fix

Resource Exhaustion

Weakness Enumeration

CWE-400

Related Identifiers

CVE-2026-45047

GHSA-39QR-RC93-VHQM

Affected Products

Github.Com/Xddxdd/Bird-Lg-Go

References · 5

• https://osv.dev/vulnerability/GHSA-39qr-rc93-vhqm · Vendor Advisory
• https://github.com/xddxdd/bird-lg-go/security/advisories/GHSA-39qr-rc93-vhqm · Note
• https://github.com/xddxdd/bird-lg-go/releases/tag/v1.4.5 · Note
• https://github.com/xddxdd/bird-lg-go/commit/0ff87024cb9ed01fc5f5fdc6f4603fce4c123922 · Note
• https://github.com/xddxdd/bird-lg-go · Note