# Cloudreve: SSRF guard bypass: checkIP does not decode IPv6-transition wrappers (NAT64, IPv4-compatible, 6to4) reaching internal and cloud-metadata addresses

Advisory record · `GHSA-jvh5-97xg-v99f`

- **Identifiers:** `GHSA-jvh5-97xg-v99f` · `CVE-2026-79913` · `GO-2026-6572`
- **State:** Confirmed
- **Severity:** CVSS 6.5 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-697](https://cwe.mitre.org/data/definitions/697.html) · [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md) · [CWE-697](https://agentprime.io/advisories/tag/cwe-697.md)
- **Published:** 22 Sept 2026
- **Updated:** 1 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 22 Sept 2026, 20:40 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/cloudreve/Cloudreve/v4` (Go): affected `<4.0.0-20260715072853-1c5cad6dec7e`; fixed in `4.0.0-20260715072853-1c5cad6dec7e`

## Machine-written summary

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

> Cloudreve versions up to and including 4.0.0-20260715072853-1c5cad6dec7e (Go module github.com/cloudreve/Cloudreve/v4) have a server-side request forgery guard that fails to classify IPv6 addresses wrapping internal IPv4 addresses, such as NAT64, IPv4-compatible and 6to4 forms. An authenticated user who can use remote download can make the server fetch internal addresses, including cloud metadata endpoints, and read the responses. Upgrade to 4.0.0-20260715072853-1c5cad6dec7e, which is listed as the fixed version.

Written 1 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0040, the 34th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:12 UTC: First seen by agentprime
- 31 Oct 2026, 14:12 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-jvh5-97xg-v99f)

## Sources

- [GitHub Advisory Database: GHSA-jvh5-97xg-v99f](https://github.com/advisories/GHSA-jvh5-97xg-v99f)
- [OSV: GHSA-jvh5-97xg-v99f](https://osv.dev/vulnerability/GHSA-jvh5-97xg-v99f)
- <https://github.com/cloudreve/cloudreve/security/advisories/GHSA-jvh5-97xg-v99f>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-79913>
- <https://github.com/cloudreve/cloudreve/commit/1c5cad6dec7ec3037c6479e3a26a3909995d16a2>
- <https://github.com/cloudreve/cloudreve>
- <https://github.com/cloudreve/cloudreve/releases/tag/4.18.0>

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-jvh5-97xg-v99f>, 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-jvh5-97xg-v99f/>. Everything for agents: <https://agentprime.io/llms.txt>.