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Fencer Vulns
medium 4.3

CVE-2026-33934 json

OpenEMR's Missing Authorization in show-signature.php Allows Portal Patients to Read Staff Signatures

published 2026-03-25 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-16042

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

OpenEMR is a free and open source electronic health records and medical practice management application. Versions prior to 8.0.0.3 have a missing authorization check in `portal/sign/lib/show-signature.php` that allows any authenticated patient portal user to retrieve the drawn signature image of any staff member by supplying an arbitrary `user` value in the POST body. The companion write endpoint (`save-signature.php`) was already hardened against this same issue, but the read endpoint was not updated to match. Version 8.0.0.3 patches the issue.

Patch / fix

  • open-emr openemr 8.0.0.3

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/openemr/openemr/security/advisories/GHSA-w9w5-7x6h-657q referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

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

Affected products

  • openemr openemr

Classification

Weakness
  • CWE-639 Authorization Bypass Through User-Controlled Key
  • CWE-862 Missing Authorization

References

Sources

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.