CVE-2026-56296
Cap-go - App Existence Oracle via Unauthenticated transfer_app RPC
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.
INFO
Published Date :
July 11, 2026, 2:16 p.m.
Last Modified :
July 11, 2026, 2:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-56296
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Cap-go to a version later than 12.128.2.
- Restrict access to the transfer_app RPC function.
- Implement consistent error messages for all app ID checks.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-56296.
| URL | Resource |
|---|---|
| https://github.com/Cap-go/capgo/security/advisories/GHSA-fmm3-3qcg-85j6 | |
| https://www.vulncheck.com/advisories/cap-go-app-existence-oracle-via-unauthenticated-transfer-app-rpc |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-56296 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-56296
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-56296 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-56296 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jul. 11, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'Cap-go', 'product': 'capgo', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '12.128.2', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '12.128.2', 'versionType': 'semver'}], 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-203 Added Reference https://github.com/Cap-go/capgo/security/advisories/GHSA-fmm3-3qcg-85j6 Added Reference https://www.vulncheck.com/advisories/cap-go-app-existence-oracle-via-unauthenticated-transfer-app-rpc