Vulnerability in github.com/jm33-m0/emp3r0r/core (CVE-2026-61554)
Summary
Vulnerability in github.com/jm33-m0/emp3r0r/core (CVE-2026-61554). Risk of unauthorized operations or information disclosure. Exploitable via http_poll. Mitigation: upgrade to 0.0.0-20260531142011-aed3d81641ab or later.
Original description
The description as published by the source.
Summary
The http_poll C2 transport accepts attacker-controlled HTTP polling sessions before CBOR MsgAuth authentication is completed. A remote unauthenticated attacker can create arbitrary polling sessions and send request bodies that are forwarded into the C2 dispatch path. This can consume server resources and trigger pre-auth C2 processing.
Details
The plain HTTP C2 server starts the HTTP polling listener and forwards requests into HandleHTTPServerSession:
// core/internal/cc/server/c2_http_server.go
mux.HandleFunc(c2Path, func(w http.ResponseWriter, req *http.Request) {
stream, err := transport.HandleHTTPServerSession(w, req, &live.RuntimeConfig.MalleableC2)
...
if stream != nil {
go cborStreamAccept(transport.NewStreamTransport(stream, req.RemoteAddr))
}
})
The HTTP polling handler accepts an attacker-supplied sessionID and init=1 cookie, then creates and stores a server-side stream before authentication:
// core/internal/transport/c2channel_http.go
if isInit {
stream = newHTTPServerStream(sessionID)
w.WriteHeader(http.StatusOK)
return stream, nil
}
POST bodies for that unauthenticated session are read and queued before CBOR authentication rejects them:
// core/internal/transport/c2channel_http.go
case http.MethodPost:
data, err := io.ReadAll(req.Body)
if err == nil && len(data) > 0 {
select {
case stream.readCh <- data:
w.WriteHeader(http.StatusOK)…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-61554 has been found in github.com/jm33-m0/emp3r0r/core.
Attackers can target a specific entry point like http_poll over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade github.com/jm33-m0/emp3r0r/core to 0.0.0-20260531142011-aed3d81641ab or later.
If unsure, ask your IT team or search "github.com/jm33-m0/emp3r0r/core CVE-2026-61554" on the vendor's site.
CVE-2026-61554 (github.com/jm33-m0/emp3r0r/core) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: http_poll / MsgAuth / HandleHTTPServerSession / sessionID
Patched: 0.0.0-20260531142011-aed3d81641ab — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in github.com/jm33-m0/emp3r0r/core. Attackers reach the vulnerable code path via http_poll without authentication.
Check the vendor advisory for the affected versions of github.com/jm33-m0/emp3r0r/core. Attack surface: http_poll / MsgAuth / HandleHTTPServerSession / sessionID.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 0.0.0-20260531142011-aed3d81641ab.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/jm33-m0/emp3r0r/core' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/jm33-m0/emp3r0r/core' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/jm33-m0/emp3r0r/coreを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/jm33-m0/emp3r0r/core to 0.0.0-20260531142011-aed3d81641abステージング環境で 0.0.0-20260531142011-aed3d81641ab に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- web github.com
- web github.com
- web github.com