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CVE-2026-63440 Details

Description

2FAuth is a web app to manage Two-Factor Authentication (2FA) accounts and generate their security codes. Prior to 8.0.0, the otpauth image-fetch path validates a hostname through ValidatesUrls::isExternalHost() and then lets IconService::storeRemoteImage() resolve the same hostname again for the HTTP request. When external otpauth image fetching is enabled, an authenticated user controlling low-TTL authoritative DNS can return a public address during validation and an internal address during the later connection, bypassing the private-address deny list to reach loopback, private-network, link-local, or cloud metadata endpoints. This issue is fixed in version 8.0.0.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:5.9 MEDIUMVector:CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://github.com/Bubka/2FAuth/commit/52e9db94f2da2a6231d77c49537d6d88ce948ee1	[email protected]
https://github.com/Bubka/2FAuth/releases/tag/v8.0.0	[email protected]
https://github.com/Bubka/2FAuth/security/advisories/GHSA-22mh-gmrh-gpwg	[email protected]

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-367	Time-of-check Time-of-use (TOCTOU) Race Condition	[email protected]
CWE-918	Server-Side Request Forgery (SSRF)	[email protected]

Affected Products

No affected product data is available for this CVE.

Change History

1 change record found show changes