# CVE-2026-126493: OpenEMR before 8.5.0 Stored XSS via OnsitePortalActivity tableArgs

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

OpenEMR before 8.5.0 contains a stored cross-site scripting vulnerability that allows low-privileged patient portal users to inject JavaScript via the tableArgs field of the onsiteportalactivity API. Attackers can store a payload with spaces that breaks out of an unquoted data-delete-id attribute, executing script when providers click the delete button on the audit review page.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- openemr / openemr: ≥ 0; < 8.5.0 (affected, semver); 8.5.0 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 4.8 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N; source: CNA: VulnCheck

- CVSS 4.0: 4.8 (medium); CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.24% as of 2026-11-13; percentile 14.53%

- SSVC: exploitation poc; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-79

## Exploit evidence

- exploit: https://github.com/openemr/openemr/security/advisories/GHSA-r4hm-frcj-qr39 (ADP: CISA-ADP)

## References

- https://github.com/openemr/openemr/security/advisories/GHSA-r4hm-frcj-qr39 (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/openemr-before-8.5.0-stored-xss-via-onsiteportalactivity-tableargs (CNA: VulnCheck; third-party-advisory)

- https://github.com/openemr/openemr/security/advisories/GHSA-r4hm-frcj-qr39 (ADP: CISA-ADP; exploit)

- https://github.com/openemr/openemr/security/advisories/GHSA-r4hm-frcj-qr39 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/openemr-before-8.5.0-stored-xss-via-onsiteportalactivity-tableargs (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-126493; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126493; retrieved 2026-11-13; source updated 2026-11-13

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-126493; retrieved 2026-11-13; source updated Not reported

Revision: f209c3e68840c28d1d85b3285872a75a334c83d1ba292b1321d9db8feddaa87c

Canonical: https://y2.dev/cve/CVE-2026-126493

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.