CVE-2026-40507 json
OpenEMR < 8.3.0 Reflected XSS via templateHtml Parameter in Patient Portal
published 2026-08-19 2 mo ago modified 2026-10-27 13 d ago also EUVD-2026-62504
- cvss
- 6.1
- 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 27%
- public exploits
- 0
- none known
Summary
OpenEMR before 8.3.0 contains a reflected cross-site scripting vulnerability in the patient portal template import handler. The templateHtml GET parameter is reflected into the page response without sanitization. An attacker can craft a URL that executes arbitrary JavaScript in the browser of any authenticated user with Forms Administration permissions who visits the link, enabling session hijacking.
Patch / fix
- openemr openemr 8.3.0
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/openemr/openemr/security/advisories/GHSA-rmmr-8498-463g referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N |
| CNA | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| CNA | 4.0 | 5.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/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 |
Affected products
- openemr openemr
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
github.com
/openemr/openemr/commit/ba316dd1d8de1291102da3f20f64240729ff899e
patch
-
github.com
/openemr/openemr/security/advisories/GHSA-rmmr-8498-463g
vendor-advisory, exploit
-
github.com
/openemr/openemr/releases/tag/v8_3_0
release-notes
-
vulncheck.com
/advisories/openemr-reflected-xss-via-templatehtml-parameter-in-patient-portal
third-party-advisory
Sources
- CVE List CVE-2026-40507
- NVD CVE-2026-40507
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.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.