CVE-2026-39413 json
LightRAG has a JWT Algorithm Confusion Vulnerability in LightRAG API
published 2026-04-08 7 mo ago modified 2026-07-24 3 mo ago also GHSA-8ffj-4hx4-9pgf , PYSEC-2026-2592 , EUVD-2026-20601
- cvss
- 4.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- public exploits
- 0
- none known
Summary
LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.4.14, 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. This vulnerability is fixed in 1.4.14.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 7 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/HKUDS/LightRAG/security/advisories/GHSA-8ffj-4hx4-9pgf referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.2 | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| OSV | 3.1 | 4.2 | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 4.2 | CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | lightrag-hku | <1.4.14 |
1.4.14 |
Affected products
- HKUDS LightRAG
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
-
github.com
/HKUDS/LightRAG/commit/728f2e54509d93e0a44f929c7f83f2c88d6d291b
web
-
github.com
/HKUDS/LightRAG/security/advisories/GHSA-8ffj-4hx4-9pgf
web, exploit, mitigation, vendor-advisory
- github.com /github/advisory-database/issues/7373
-
nvd.nist.gov
/vuln/detail/CVE-2026-39413
advisory
-
github.com
/HKUDS/LightRAG
package
-
pypi.org
/project/lightrag-hku
package
-
github.com
/advisories/GHSA-8ffj-4hx4-9pgf
advisory
Sources
- CVE List CVE-2026-39413
- GitHub Advisory GHSA-8ffj-4hx4-9pgf
- NVD CVE-2026-39413
- OSV PYSEC-2026-2592
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