CVE-2026-56329
MEDIUMCapgo - Cross-Tenant Preview Namespace Collision via Non-Bijective Underscore Decoding
Title source: cnaDescription
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.
References (2)
Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-76qq-gg2p-pwwj)
https://github.com/Cap-go/capgo/security/advisories/GHSA-76qq-gg2p-pwwj
Third Party Advisory third-party-advisory
VulnCheck Advisory: Capgo - Cross-Tenant Preview Namespace Collision via Non-Bijective Underscore Decoding
https://www.vulncheck.com/advisories/capgo-cross-tenant-preview-namespace-collision-via-non-bijective-underscore-decoding
Scores
CVSS v3
6.4
EPSS
0.0024
EPSS Percentile
14.9%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-436
Status
published
Products (2)
Capgo/Capgo
< 12.128.2
Capgo/Capgo
12.128.2
Published
Jul 10, 2026
Tracked Since
Jul 10, 2026