Cyber Resilience

CVE-2026-56215

HighPublic PoC

Published: 20 June 2026

Published
20 June 2026
Modified
24 June 2026
KEV Added
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Patch
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CVSS Score v4 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/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 0.0023 13.5th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-56215 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability. Its CVSS base score is 8.7 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13.5th 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)

A01:2025 Broken Access Control

EU & UK References

Vulnerability details

Capgo before 12.128.12 allows authenticated users to modify their mutable public.users.email to arbitrary addresses, which the SSO provisioning endpoint trusts as an account-merge key. Attackers can pre-position their account with a victim's corporate SSO email, causing the provision-user endpoint to…

more

merge the victim's SSO identity into the attacker-controlled account.

CWE(s)
CWE-639

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1078.004 Cloud Accounts Stealth
Valid accounts in cloud environments may allow adversaries to perform actions to achieve Initial Access, Persistence, Privilege Escalation, or Defense Evasion.
attack.mitre.org →
Why these techniques?

Authz bypass in public-facing Capgo SSO provisioning directly enables exploitation of the app (T1190) to obtain/merge valid cloud accounts (T1078.004).

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

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.

AC-24 Access Control Decisions
addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

AC-3 Access Enforcement
addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

References