CVE-2026-84697

MEDIUM 5.3

Mailpit SSRF Deny List Bypass via Azure Metadata and IPv6 Prefix

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-918
Vendor	axllent
Product	mailpit
Published	Sep 2, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Affected Versions

axllent / mailpit

0 ≤ 1.31.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

euriconicacio