CVE-2026-63441: medium-severity vulnerability in Bubka 2FAuth
2FAuth: SSRF guard misses IPv6 NAT64 prefixes, allowing image fetch to reach internal/metadata targets
Published
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10Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 4.9
2FAuth is a web app to manage Two-Factor Authentication (2FA) accounts and generate their security codes. From 6.1.0 until 8.0.0, App\Services\Traits\ValidatesUrls::isPublicIp() does not recognize the 64:ff9b::/96 and 64:ff9b:1::/48 NAT64 prefixes, so an otpauth URI image parameter can pass an IPv6 literal or DNS64-synthesized address whose embedded IPv4 target is private, link-local, loopback, or cloud metadata. In a deployment with image fetching enabled and a NAT64 translation path to the internal IPv4 target, an account holder can submit the crafted URI directly, or an external attacker can induce a victim to import a crafted URI or migration payload. IconService::buildFromRemoteImage() then issues an HTTP GET to the embedded target, allowing image-shaped responses to be recovered or other endpoints to be probed blindly. This issue is fixed in version 8.0.0.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N
Affected products
Bubka · 2FAuthRelated CVEs — Bubka 2FAuth
In the same product, most dangerous first.
CVE-2024-52598HIGH2FAuth vulnerable to Server Side Request Forgery + URI validation bypass in 2fauth /api/v1/twofaccounts/previewEPSS 0.6%CVE-2026-32133HIGH2FAuth has Blind SSRF in image parameter allows internal network access and moreEPSS 0.5%CVE-2023-36816MEDIUMCross-Site Scripting (XSS) at Account creation in 2FAuthEPSS 0.5%CVE-2024-52597MEDIUM2FAuth vulnerable to stored cross-site scripting via SVG upload and direct access renderEPSS 0.4%CVE-2026-63439CRITICAL2FAuth: Reverse Proxy Guard Trusts Client-Supplied Headers Without Proxy VerificationEPSS —CVE-2026-63438CRITICAL2FAuth: Reverse Proxy Guard Auto-Creates Users With Admin Promotion From Unauthenticated Header ValueEPSS —