Description
OpenAM before 16.1.3 applies its OAuth2 Provider PKCE enforcement only to authorization requests whose response_type is exactly code, so codes issued through OpenID Connect hybrid flows (code token, code id_token, code token id_token) carry no bound challenge. An attacker who intercepts such a code can redeem it for a public client's tokens with any non-empty code_verifier.
References2
Metrics
- CVSS 3.1
-
6.8
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 4.0
-
7.6
HIGH
Score source: CNA
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/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 — exploit probability
- 0% percentile: 9 · as of 10 November 2026
- CWE
- CWE-285
Could this be exploited in your environment?
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