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TI-2026-86114 Aliases CVE-2026-63441

Server-side request forgery in 2FAuth image fetching via NAT64 addresses

Priority LOW 22CWE-918Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

2FAuth versions from 6.1.0 before 8.0.0 do not recognize the NAT64 prefixes 64:ff9b::/96 and 64:ff9b:1::/48 in its private address check. An account holder, or an external attacker who gets a victim to import a crafted otpauth URI or migration payload, can make the image fetch reach an internal IPv4 target embedded in an IPv6 address, such as a private, loopback, link-local or cloud metadata address, in deployments with image fetching enabled and a NAT64 path. This is server-side request forgery (CWE-918) that can recover image-shaped responses or probe other endpoints blindly.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

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.

Why it matters now

EPSS 0.0031 24th percentileScored 2026-11-07
Fix Fixed 2FAuth (Bubka): 8.0.0

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
Bubka2FAuth6.1.0 to before 8.0.08.0.0Patch availableCNA
  • 2FAuth VendorBubka Affected 6.1.0 to before 8.0.0 Fixed in 8.0.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:2fauth:2fauth:*:*:*:*:*:*:*:*——Bubka
  • cpe:2.3:a:2fauth:2fauth:*:*:*:*:*:*:*:* Versions — — ·Bubka

Remediation

Update 2FAuth to version 8.0.0, which fixes this issue. The sources list no fixed version for other products.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

  • Fix · CNA 2FAuth (Bubka) Fixed in 8.0.0

Timeline

  1. 2026-11-06 Threatist record created from CVE-2026-63441

References

Other 3

  • TI-2026-24670 2FAuth has Blind SSRF in image parameter allows internal network access and more CVSS 4.0HIGH 7.8
  • TI-2024-35258 2FAuth vulnerable to Server Side Request Forgery + URI validation bypass in 2fauth /api/v1/twofaccounts/preview CVSS 3.1HIGH 7.5
  • TI-2025-28827 A group deletion race condition in 2FAuth v5.5.0 causes data inconsistencies and orphaned… CVSS 3.1MEDIUM 6.5
  • TI-2024-35257 2FAuth vulnerable to stored cross-site scripting via SVG upload and direct access render CVSS 3.1MEDIUM 6.1
  • TI-2023-18610 Cross-Site Scripting (XSS) at Account creation in 2FAuth CVSS 3.1MEDIUM 6.1
  • TI-2026-86111 Reverse proxy guard in 2FAuth accepts unauthenticated user headers CVSS 3.1CRITICAL 9.8
See all 9 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences