CVE-2026-56296 | Cap-go before 12.128.2 contains an information disclosure vu… | CVSS 5.3 MEDIUM

Description

Cap-go before 12.128.2 contains an information disclosure vulnerability in the public.transfer_app RPC function that returns distinct error messages for existing versus non-existing app IDs. Unauthenticated attackers can enumerate valid app IDs by observing error message differences when calling transfer_app with only the publishable API key.

Metadata

CVE ID: CVE-2026-56296
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-20 12:49 UTC
Published: 2026-07-11 13:00 UTC
Last updated: 2026-07-11 13:00 UTC
Primary CWE: CWE-203
Observable Discrepancy
Vendor / Product: Cap-go / capgo
Sources: cve.org · NVD

Severity & Metrics

5.3 MEDIUM CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected products (1)

Vendor	Product	Platform	Versions
Cap-go	capgo	—	0 < 12.128.2, 12.128.2

Weakness (CWE)

CWE	Source	Description
CWE-203	cna	Observable Discrepancy

CVSS scores (2)

Score	Severity	Version	Source	Vector
6.9	MEDIUM	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
5.3	MEDIUM	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References (2)

GitHub Security Advisory (GHSA-fmm3-3qcg-85j6) https://github.com/Cap-go/capgo/security/advisories/GHSA-fmm3-3qcg-85j6
VulnCheck Advisory: Cap-go - App Existence Oracle via Unauthenticated transfer_app RPC https://www.vulncheck.com/advisories/cap-go-app-existence-oracle-via-unauthenticated-transfer-app-rpc