CVE-2026-123542 PUBLISHED

OpenAM before 16.1.4 PKCE Bypass in OAuth 2.0 Device Authorization Flow

Assigner: VulnCheck
Reserved: 06.11.2026 Published: 08.11.2026 Updated: 08.11.2026

OpenAM before 16.1.4 fails to enforce PKCE in the OAuth 2.0 device authorization flow, never validating the code verifier when device codes are exchanged for tokens. Attackers who obtain an approved device code from client logs or shared device storage can redeem it for access and ID tokens to impersonate the user.

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 7.6

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	High	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS Score: 6.8

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	OpenIdentityPlatform
Product	OpenAM
Versions	Default: unaffected affected from 0 to 16.1.4 (excl.) Version 16.1.4 is unaffected

Credits

manus-pi reporter
vharseko remediation developer
maximthomas remediation reviewer
tsujiguchitky remediation reviewer
manus-use reporter

References

Problem Types

Improperly Implemented Security Check for Standard CWE