Capgo - Cross-Tenant Preview Namespace Collision via Non-Bijective Underscore Decoding | Advisories

Advisories

Capgo - Cross-Tenant Preview Namespace Collision via Non-Bijective Underscore Decoding

severity: medium
date: 7/10/2026
Affecting: Capgo >= 0, < 12.128.2
CVE: CVE-2026-56329
CWE: CWE-436 Interpretation Conflict
CVSS: 5.3
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L
References: GitHub Security Advisory (GHSA-76qq-gg2p-pwwj)
Credit: Judel777
Description: Capgo before 12.128.2 contains a cross-tenant preview namespace collision vulnerability caused by non-bijective decoding of double underscores to dots in preview hostname parsing. Attackers can register app IDs with underscores that collide with other tenants' dotted app IDs, causing preview misrouting and denial of preview access for victim applications.

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