CVE-2026-44203
OpenAM has pre-auth Reflected XSS in OAuth2 / OIDC response_mode=form_post via state parameter (FormPostResponse.ftl)
9.3
CRITICAL
CVSS 3.1
Description
### Summary The OAuth 2.0 / OpenID Connect authorization endpoint does not sufficiently sanitize certain user-supplied parameters before incorporating them into the HTML response generated for the `form_post` response mode. This may allow an attacker to inject content into the rendered page in the context of the OpenAM origin.
How to fix CVE-2026-44203
To remediate CVE-2026-44203, upgrade the affected package to a fixed version below.
- —upgrade to 16.1.1 or later
Is CVE-2026-44203 being exploited?
No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-44203.
Affected packages (1)
- >= 13.0.0, < 16.1.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N |