vulnerability / NVI-00012947 / Revision 3
lightrag-hku: SSRF via IPv6-transition address bypass (NAT64, IPv4-compatible, 6to4) of the native-markdown image-download guard
GitHub lists this reviewed advisory for lightrag-hku. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
7.1 high
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
7.1 HIGH (3.1)
security-advisories@github.com severity; no combined Null risk score.
0.264%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.18228. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
lightrag-hku
source listed< 1.5.5
## Summary LightRAG's native markdown parser downloads external images referenced by an uploaded markdown or textpack document. The only SSRF guard, `_validated_addresses()` in `lightrag/parser/markdown/parser.py`, resolves the image host and rejects it when the resolved IP is not `is_global`. That check is evaluated on the raw resolved address and never decodes IPv6 transition wrappers that embed an internal IPv4. Python's `ipaddress` classifies a NAT64 (`64:ff9b::/96` and the RFC 8215 `64:ff9b:1::/48` prefix), IPv4-compatible (`::a.b.c.d`), or 6to4 (`2002::/16`) literal that wraps an internal IPv4 as globally routable, so the guard passes it. On a host with NAT64/DNS64 routing the request is then delivered to the embedded internal target (loopback, RFC1918, or a cloud metadata endpoint), and the fetched body is ingested. The plain and IPv4-mapped (`::ffff:`) forms of the same internal address are correctly blocked, so this is an encoding that defeats the existing filter. ## Affected component and versions - Package: `lightrag-hku` (LightRAG), the native markdown image-download path. - Component: `lightrag/parser/markdown/parser.py`, guard `_validated_addresses()` (the `if not
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-vv3m-f8x4-7377 ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
- CVE-2026-85740 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2026-85740 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 2 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.