# pyLoad: SSRF guard bypass via IPv6 6to4/NAT64 transition wrappers of internal IPs

Advisory record · `GHSA-m5x5-28jr-gpjj`

- **Identifiers:** `GHSA-m5x5-28jr-gpjj` · `CVE-2026-48737` · `PYSEC-2026-2995`
- **State:** Confirmed
- **Severity:** CVSS 4.9 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md)
- **Published:** 9 Jul 2026
- **Updated:** 13 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 9 Jul 2026, 13:35 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `pyload-ng` (PyPI): affected `<=0.5.0b3.dev100`; no fixed version yet

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> pyload-ng up to 0.5.0b3.dev100 has an SSRF guard bypass: IPv6 6to4 and NAT64 addresses that embed internal IPv4 addresses are treated as globally routable. A user who can add links can make the server reach internal endpoints where those addresses route. No fixed version is listed.

Written 6 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 4.9 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:L`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0029, the 21st percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:02 UTC: First seen by agentprime
- 31 Oct 2026, 15:02 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-m5x5-28jr-gpjj)

## Sources

- [GitHub Advisory Database: GHSA-m5x5-28jr-gpjj](https://github.com/advisories/GHSA-m5x5-28jr-gpjj)
- [OSV: GHSA-m5x5-28jr-gpjj](https://osv.dev/vulnerability/GHSA-m5x5-28jr-gpjj)
- <https://github.com/pyload/pyload/security/advisories/GHSA-m5x5-28jr-gpjj>
- <https://github.com/pyload/pyload>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-m5x5-28jr-gpjj>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-m5x5-28jr-gpjj/>. Everything for agents: <https://agentprime.io/llms.txt>.