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.
CVE-2026-40507
MEDIUMPre-NVD 6.16.1—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 6.1 from GitHub Security Advisory published 2026-08-19. a secondary CVSS source baseline 6.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.1
- EG Score
- 6.1(high)
- EG Risk
- 32(Track)EG Risk 32/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity61% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 16%
- KEV
- Not listed
Published
August 19, 2026
Last Modified
August 19, 2026
Advisory Details (4)
Auto-updated Aug 19, 2026🔬 Proof of concept available. Patch available. Sources: github_release, github_commit, github.
generic
OpenEMR < 8.3.0 Reflected XSS via templateHtml Parameter in Patient Portal | Advisories | VulnCheck
https://www.vulncheck.com/advisories/openemr-reflected-xss-via-templatehtml-parameter-in-patient-portalgithub_commit
commit ba316dd1d8de (openemr/openemr)
Fix landed in openemr/openemr commit ba316dd1d8de — awaiting tagged release
https://github.com/openemr/openemr/commit/ba316dd1d8de1291102da3f20f64240729ff899egithub_release Patch Available
OpenEMR 8.3.0
Patch available: openemr/openemr v8_3_0
https://github.com/openemr/openemr/releases/tag/v8_3_0github Patch Available🟡 PoC Available
/portal/import_template.php templateHtml Reflected Cross-Site Scripting · Advisory · openemr/openemr · GitHub
https://github.com/openemr/openemr/security/advisories/GHSA-rmmr-8498-463gVendor Advisories for CVE-2026-40507(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 6× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 15:50 UTCEG score recompute
- 2026-08-20 15:50 UTCGHSA enrichment
- 2026-08-19 15:24 UTCEG score recompute
- 2026-08-19 14:57 UTCEG score recompute
- 2026-08-19 14:57 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-40507?
CVE-2026-40507 is a medium vulnerability published on August 19, 2026. 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…
When was CVE-2026-40507 disclosed?
CVE-2026-40507 was first published in the National Vulnerability Database on August 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40507 actively exploited?
CVE-2026-40507 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 84.2% of all scored CVEs.
What is the CVSS score of CVE-2026-40507?
CVE-2026-40507 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-40507?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40507, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-40507
Is Your Infrastructure Affected by CVE-2026-40507?
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