openemr: Deserialization of Untrusted Data
CVE-2026-126322 is a high-severity deserialization of untrusted data vulnerability in openemr, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 8.3.0 as the first without the flaw, so updating openemr to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.39% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update openemr to 8.3.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.1 | High | CNA (vulncheck.com) |
Official description
OpenEMR before 8.3.0 contains an unsanitized deserialization vulnerability that allows authenticated attackers to control patient-matching criteria by supplying a crafted serialized key parameter. Attackers can send serialized arrays to interface/orders/patient_match_dialog.php to enumerate patients or force matches that associate lab orders with the wrong patient.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Other references
Other vulnerabilities in openemr
- 7.1 High severity
- 8.8 High severity
- 7.6 High severity
- 7.2 High severity
- 7.7 High severity
- 8.8 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.2 High severity
- 9.8 Critical severity
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