GHSA-39QR-RC93-VHQM
Vulnerability from github – Published: 2026-05-11 16:17 – Updated: 2026-05-11 16:17Summary
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:
```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)
// ...
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/xddxdd/bird-lg-go"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.0.0-20260507060110-0ff87024cb9e"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-45047"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-05-11T16:17:48Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Summary\nThe `apiHandler` (and similarly `webHandlerTelegramBot`) processes user-provided JSON payloads by directly using `json.NewDecoder(r.Body).Decode(\u0026request)` 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\u0027s JSON decoder attempts to allocate memory for the entire parsed structure, this rapidly exhausts the host\u0027s physical RAM or container limits, leading to an unrecoverable `fatal error: runtime: out of memory`. \n\nThis causes the Linux OOM Killer to instantly terminate the entire `bird-lg-go` daemon, resulting in a severe Remote Denial of Service (RDoS).\n\n### Details\nIn `api.go`:\n```go\nfunc apiHandler(w http.ResponseWriter, r *http.Request) {\n var request apiRequest\n // VULNERABILITY: No http.MaxBytesReader protection before JSON decode\n err := json.NewDecoder(r.Body).Decode(\u0026request) \n // ...",
"id": "GHSA-39qr-rc93-vhqm",
"modified": "2026-05-11T16:17:48Z",
"published": "2026-05-11T16:17:48Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/xddxdd/bird-lg-go/security/advisories/GHSA-39qr-rc93-vhqm"
},
{
"type": "WEB",
"url": "https://github.com/xddxdd/bird-lg-go/commit/0ff87024cb9ed01fc5f5fdc6f4603fce4c123922"
},
{
"type": "PACKAGE",
"url": "https://github.com/xddxdd/bird-lg-go"
},
{
"type": "WEB",
"url": "https://github.com/xddxdd/bird-lg-go/releases/tag/v1.4.5"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Bird-lg-go has a Fatal Out-of-Memory (OOM) Denial of Service via Unbounded JSON Decoding"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.