OpenEMR: Unauthenticated Open Redirect via OIDC End Session Endpoint

published 2026-11-05 3 d ago modified 2026-11-06 2 d ago also EUVD-2026-117776

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits: 0; none known

OpenEMR is a free and open source electronic health records and medical practice management application. Prior to 8.3.0, userSessionLogout() in src/RestControllers/AuthorizationController.php uses decodeToken() to process an id_token_hint without verifying its signature and, when the referenced trusted session is absent, redirects to the caller-supplied post_logout_redirect_uri before validating it against the client's registered redirect URIs. An unauthenticated attacker can craft a logout link that sends a user to an arbitrary external site and invalidates the user's session, enabling convincing phishing flows from the legitimate logout endpoint. The endpoint is reachable when the OpenEMR REST API is enabled. This issue is fixed in version 8.3.0.

Patch / fix

links 3

github.com/openemr/openemr@50f789f commit
github.com/openemr/openemr#13133 pull request
github.com/openemr/openemr/releases/tag/v8_3_0 release

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Affected products

openemr openemr

Classification

Weakness

CWE-601 URL Redirection to Untrusted Site

References

Sources

CVE List CVE-2026-103019
NVD CVE-2026-103019

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary