CVE-2026-63441
2FAuth: SSRF guard misses IPv6 NAT64 prefixes, allowing image fetch to reach internal/metadata targets
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| 2FAuth Bubka |
>= 6.1.0, < 8.0.0 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 4.9 medium |
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 | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/Bubka/2FAuth/security/advisories/GHSA-wc8m-7c5g-xrrcCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/Bubka/2FAuth/commit/df19e7533082671ecc2e0c735adcd51e93b1cb4cCNA: GitHub_M · x_refsource_MISC
- https://github.com/Bubka/2FAuth/releases/tag/v8.0.0CNA: GitHub_M · x_refsource_MISC
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