CVE-2026-126421 json
OpenEMR before 8.5.0 Denial of Service via labs_ajax.php Label Count
published 18d ago modified 2d ago also EUVD-2026-125022 , GHSA-3j3r-w7q7-h9fj
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository openemr/openemr. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- 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 21%
- public exploits
- 0
- none known
Summary
OpenEMR before 8.5.0 contains an uncontrolled resource consumption vulnerability that allows authenticated users with patients/med access to exhaust PHP workers via an unbounded count parameter. Attackers can send print_labels requests to labs_ajax.php with huge counts, forcing mPDF page and barcode generation that makes OpenEMR unavailable.
Patch / fix
- openemr openemr 8.5.0
Is CVE-2026-126421 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.28% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-14).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| CNA | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
| CNA | 4.0 | 5.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/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 |
| NVD | 3.1 | 4.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L |
Affected products
- openemr openemr
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
github.com
/openemr/openemr/security/advisories/GHSA-3j3r-w7q7-h9fj
vendor-advisory, advisory
-
vulncheck.com
/advisories/openemr-before-8.5.0-denial-of-service-via-labs-ajax-php-label-count
third-party-advisory
Sources
- CVE List CVE-2026-126421
- NVD CVE-2026-126421
- Maintainer advisory GHSA-3j3r-w7q7-h9fj
Fencer Intel 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.
The maintainers of openemr/openemr published their own advisory on GitHub. Reviewed sources take precedence over it.