Cyber Resilience

CVE-2026-56243

HighPublic PoC

Published: 23 June 2026

Published
23 June 2026
Modified
23 June 2026
KEV Added
Patch
CVSS Score v4 8.6 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/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 0.0027 19.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-56243 is a high-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 19.1th 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 a security control bypass vulnerability where the PostgREST/RLS plane accepts plaintext API keys through the capgkey header despite enforce_hashed_api_keys being enabled. Attackers can bypass org-level hashed-key enforcement by sending plaintext API keys directly to the PostgREST/RLS…

more

plane to access protected resources.

CWE(s)

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.
Why these techniques?

Bypass of API key hashing enforcement on public-facing PostgREST/RLS endpoint directly enables exploitation of the exposed application for unauthorized access.

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.

addresses: CWE-288

Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.

addresses: CWE-288

Users can identify logons via alternate paths or channels by reviewing the previous logon time.

addresses: CWE-288

Adaptive requirements can apply across access paths, reducing the ability to bypass authentication via alternate channels or paths.

addresses: CWE-288

Centralized IdPs close alternate authentication paths that enable bypass.

addresses: CWE-288

Enforces authentication for non-organizational users, making it harder to bypass via alternate paths or channels.

addresses: CWE-288

Requires authentication to occur exclusively over the isolated trusted path, directly preventing bypass via alternate or untrusted channels.

References