Vulnerability in lightrag-hku (CVE-2026-39413)
Summary
Vulnerability in lightrag-hku (CVE-2026-39413). Confidential information can be exposed externally. Exploitable via validate_token. Mitigation: upgrade to 1.4.14 or later.
Original description
The description as published by the source.
Summary
The LightRAG API is vulnerable to a JWT algorithm confusion attack where an attacker can forge tokens by specifying 'alg': 'none' in the JWT header. Since the jwt.decode() call does not explicitly deny the 'none' algorithm, a crafted token without a signature will be accepted as valid, leading to unauthorized access.
Details
In lightrag/api/auth.py at line 128, the validate_token method calls:
payload = jwt.decode(token, self.secret, algorithms=[self.algorithm])
This allows any algorithm listed in the token's header to be processed, including 'none'. The code does not explicitly specify that 'none' is not allowed, making it possible for an attacker to bypass authentication.
PoC
An attacker can generate a JWT with the following structure:
{
"header": {
"alg": "none",
"typ": "JWT"
},
"payload": {
"sub": "admin",
"exp": 1700000000,
"role": "admin"
}
}
Then send a request like:
curl -H "Authorization: Bearer eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJzdWIiOiJhZG1pbiIsImV4cCI6MTcwMDAwMDAwMCwicm9sZSI6ImFkbWluIn0." http://localhost:8000/api/protected-endpoint
Impact
An attacker can impersonate any user, including administrators, by forging a JWT with 'alg': 'none', gaining full access to protected resources without needing valid credentials.
Recommended Fix
Explicitly specify allowed algorithms and exclude 'none'. Modify the validate_token method to:
allowed_algorithms =…
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-2026-39413 has been found in lightrag-hku.
Attackers can target a specific entry point like validate_token over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 4.2/10.
What to do: upgrade lightrag-hku to 1.4.14 or later.
If unsure, ask your IT team or search "lightrag-hku CVE-2026-39413" on the vendor's site.
CVE-2026-39413 (lightrag-hku) — CWE-347 / CVSS v3 4.2
Attack vector: remote (network-reachable)
Attack surface: validate_token
Patched: 1.4.14 — 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-347) exists in lightrag-hku. Attackers reach the vulnerable code path via validate_token.
Check the vendor advisory for the affected versions of lightrag-hku. Attack surface: validate_token.
Severity: Medium (CVSS 4.2/10). Confidential information can be exposed externally.
Update to 1.4.14.
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 'lightrag-hku' . 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 'lightrag-hku' . | 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
lightrag-hku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 lightrag-hku to 1.4.14ステージング環境で 1.4.14 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
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com