Vulnerability in python-engineio (CVE-2026-48802)
Summary
Vulnerability in python-engineio (CVE-2026-48802). Risk of unauthorized operations or information disclosure. Exploitable via connect. Mitigation: upgrade to 4.13.2 or later.
Original description
The description as published by the source.
Impact
An attacker can cause the creation of unnecessary background threads in the python-engineio server by exploiting the heartbeat mechanism, which launches a thread when a new connection is received, and when the client sends a PONG packet.
Note: this issue primarily affects synchronous servers. Asynchronous servers allocate background tasks instead of physical threads, which are lightweight and less likely to cause denial of service. However, the fix that was implemented was also applied to the asynchronous case.
Patches
Version 4.13.2 addresses this issue as follows:
- The initial background thread (or async task( for heartbeat management is only launched if a client passes authentication in the
connecthandler. - The server now ensures that there is only one background heatbeat thread (or async task) per client at a given point in time. Out of sequence PONG packets are now discarded when an active heartbeat thread is already running.
Source: GitHub Security Advisories (Global) 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-2026-48802 has been found in python-engineio.
Attackers can target a specific entry point like connect over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade python-engineio to 4.13.2 or later.
If unsure, ask your IT team or search "python-engineio CVE-2026-48802" on the vendor's site.
CVE-2026-48802 (python-engineio) — CWE-770 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: connect
Patched: 4.13.2 — 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-770) exists in python-engineio. Attackers reach the vulnerable code path via connect without authentication.
Check the vendor advisory for the affected versions of python-engineio. Attack surface: connect.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 4.13.2.
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 'python-engineio' . 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 'python-engineio' . | 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
python-engineio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 python-engineio to 4.13.2ステージング環境で 4.13.2 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
- package github.com
- web github.com
- web github.com
- web security-advisories@github.com