PatchSiren cyber security CVE debrief
CVE-2026-56329 Capgo CVE debrief
A medium-severity vulnerability, CVE-2026-56329, was found in Capgo, a cross-tenant preview namespace collision issue. This vulnerability is 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. Users should review official advisories and assess their exposure.
- Vendor
- Capgo
- Product
- Unknown
- CVSS
- MEDIUM 5.3
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-10
- Original CVE updated
- 2026-07-10
- Advisory published
- 2026-07-10
- Advisory updated
- 2026-07-10
Who should care
Users of Capgo, especially those with multiple tenants, should be aware of this vulnerability and take necessary precautions to prevent exploitation. They should review their deployments, assess exposure, and implement compensating controls if necessary.
Technical summary
CVE-2026-56329 is a cross-tenant preview namespace collision vulnerability in Capgo. The issue arises from non-bijective decoding of double underscores to dots in preview hostname parsing. This allows attackers to register app IDs with underscores that collide with other tenants' dotted app IDs, causing preview misrouting and denial of preview access for victim applications. Affected users should verify their deployments and plan for vendor-supported updates or mitigations.
Defensive priority
Medium
Recommended defensive actions
- Inventory and verify Capgo installations
- Restrict app ID registration to prevent collisions
- Monitor preview hostname parsing for suspicious activity
- Implement compensating controls to prevent preview misrouting
- Apply vendor remediation when available
- Review official advisories for affected scope and severity
- Track exceptions and retest remediated assets
Evidence notes
The CVE record was published on 2026-07-10T15:16:42.727Z and was last modified on 2026-07-10T17:17:00.643Z. The NVD entry is currently Deferred. Evidence is limited to CVE and NVD information. Defenders should verify affected scope and vendor guidance.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-10T15:16:42.727Z and has not been modified since then. The NVD entry is currently Deferred.