Cyber Resilience

CVE-2026-56300

HighPublic PoC

Published: 30 June 2026

Published
30 June 2026
Modified
01 July 2026
KEV Added
Patch
CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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
EPSS Score 0.0035 26.9th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-56300 is a high-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Permission Groups Discovery (T1069); ranked at the 26.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Capgo before 12.128.2 contains unauthenticated security definer RPC functions get_user_id and get_org_perm_for_apikey that expose API key validity oracles and user UUID disclosure. Unauthenticated attackers using the public API key can validate leaked keys, enumerate users and apps, and determine permission…

more

levels, significantly increasing the actionability of compromised credentials.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1069 Permission Groups Discovery Discovery
Adversaries may attempt to discover group and permission settings.
T1069.003 Cloud Groups Discovery
Adversaries may attempt to find cloud groups and permission settings.
T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
T1087.004 Cloud Account Discovery
Adversaries may attempt to get a listing of cloud accounts.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
Why these techniques?

Direct information disclosure of user UUIDs, org permissions, and API key validity enables account discovery, cloud permission group enumeration, and validation of compromised credentials.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-36719Shared CWE-200
CVE-2026-56242Shared CWE-200
CVE-2026-36539Shared CWE-200
CVE-2024-48310Shared CWE-200
CVE-2026-33163Shared CWE-200
CVE-2025-24899Shared CWE-200
CVE-2026-37453Shared CWE-200
CVE-2026-33981Shared CWE-200
CVE-2026-56244Shared CWE-200
CVE-2024-54961Shared CWE-200

Affected Assets

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-200

Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.

addresses: CWE-200

Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.

addresses: CWE-200

Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.

addresses: CWE-200

By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.

addresses: CWE-200

Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.

addresses: CWE-200

Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.

addresses: CWE-200

Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.

addresses: CWE-200

Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.

Hardening callouts derived

Configuration rules from DISA STIG baselines that reduce the attack surface for weaknesses of the type cited by this CVE. Derived transitively via CVE→CWE→STIG over `controls_xwalks` (authoritative rows only).

Ubuntu 22.04 (1 rule)
  • V-260470 Ubuntu 22.04 LTS, when booted, must require authentication upon booting into single-user and maintenance modes. via CWE-200
Ubuntu 24.04 (2 rules)
  • V-270647 Ubuntu 24.04 LTS must not have the telnet package installed. via CWE-200
  • V-270675 Ubuntu 24.04 LTS when booted must require authentication upon booting into single-user and maintenance modes. via CWE-200
Windows 10 (1 rule)
  • V-220737 Administrative accounts must not be used with applications that access the Internet, such as web browsers, or with potential Internet sources, such as email. via CWE-200
Windows Server 2016 (1 rule)
  • V-224974 Domain-created Active Directory Organizational Unit (OU) objects must have proper access control permissions. via CWE-200
Windows Server 2019 (1 rule)
  • V-205743 Windows Server 2019 organization created Active Directory Organizational Unit (OU) objects must have proper access control permissions. via CWE-200
Windows Server 2022 (1 rule)
  • V-254395 Windows Server 2022 organization created Active Directory Organizational Unit (OU) objects must have proper access control permissions. via CWE-200

References