CVE-2026-85740
LightRAG: SSRF via IPv6-transition address bypass (NAT64, IPv4-compatible, 6to4) of the native-markdown image-download guard
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, _validated_addresses in lightrag/parser/markdown/parser.py evaluates the literal resolved address with ipaddress.is_global without consistently classifying an IPv4 address embedded in an IPv6 transition wrapper. A caller who can upload a Markdown or textpack document can supply an external image URL using NAT64 64:ff9b::/96 or an IPv4-compatible form that embeds a loopback, private, or cloud-metadata IPv4 address. On a deployment with compatible NAT64 or DNS64 routing, _download and _build_guarded_opener accept the wrapper and fetch the internal resource, whose body is then ingested. Current interpreter behavior already blocks some RFC 8215 and 6to4 forms, but the fixed guard handles all documented wrappers without becoming more permissive than the standard library. This issue is fixed in version 1.5.5.
Public exploit
A reference of the record is tagged as an exploit or proof of concept: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
- https://github.com/HKUDS/LightRAG/security/advisories/GHSA-vv3m-f8x4-7377 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 18 days later
· 18 days later
Published
- 6 days later
· 6 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N |
| NVDNVD · Deferred | 3.1 | High7.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.26% · top 82% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIlightrag-hkuGHSA-vv3m-f8x4-7377 (opens in a new tab)
References (6)
- https://github.com/HKUDS/LightRAG/security/advisories/GHSA-vv3m-f8x4-7377 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/HKUDS/LightRAG/pull/3426 (opens in a new tab)x_refsource_MISC
- https://github.com/HKUDS/LightRAG/commit/9207e7fd10cf6df3cf26e3dd1921490b34a2f132 (opens in a new tab)x_refsource_MISC
- https://github.com/HKUDS/LightRAG/commit/a25862177a9b00e0edb870778a42b4155924de09 (opens in a new tab)x_refsource_MISC
- https://github.com/HKUDS/LightRAG/commit/c598545aa0084a427bcb19a84ade5e0ec31fa673 (opens in a new tab)x_refsource_MISC
- https://github.com/HKUDS/LightRAG/releases/tag/v1.5.5 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-vv3m-f8x4-7377 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-85740)Record last updated .