What is CVE-2026-56329?

CVE-2026-56329 is a medium-severity vulnerability in Capgo, classified under CWE-436. CVSS score: 6.4/10. Published 2026-07-10.

How severe is CVE-2026-56329?

Medium severity. CVSS v3 base score is 6.4 out of 10.

Vulnerability in Capgo

CVE-2026-56329

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.

Published 2026-07-10 · last modified 2026-07-10.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (23.6th percentile), scored 2026-10-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 23.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Capgo — versions 0, 12.128.2

Weakness classification (CWE)

CWE-436

References

github.com/Cap-go/capgo/security/advisories/GHSA-76qq-gg2p-pwwj (vendor-advisory)
www.vulncheck.com/advisories/capgo-cross-tenant-preview-namespace-collision-via… (third-party-advisory)

Frequently asked questions

What is CVE-2026-56329?: CVE-2026-56329 is a medium-severity vulnerability in Capgo, classified under CWE-436. CVSS score: 6.4/10. Published 2026-07-10.
How severe is CVE-2026-56329?: Medium severity. CVSS v3 base score is 6.4 out of 10.