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CVE-2026-41258NVD status: Deferred

openmrs-core: Improper Control of Generation of Code

CVE-2026-41258 is a critical-severity improper control of generation of code vulnerability in openmrs-core from OpenMRS, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected openmrs-core versions: >= 2.7.0 < 2.7.9; >= 2.8.0 < 2.8.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.32% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of openmrs-core you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
Openmrsopenmrs-core>= 2.7.0 < 2.7.9; >= 2.8.0 < 2.8.6Not stated

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
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (github.com).

Official description

OpenMRS is an open source electronic medical record system platform. From 2.7.0 to before 2.7.9 and 2.8.6, the ConceptReferenceRangeUtility.evaluateCriteria() method in OpenMRS Core evaluates database-stored criteria strings as Apache Velocity templates without any sandbox configuration. The VelocityEngine is initialized with only logging properties and noSecureUberspector, leaving the default UberspectImpl in place, which allows unrestricted Java reflection through template expressions. A user with the Manage Concepts privilege can store a malicious Velocity template expression in a concept's reference range criteria field. This payload is then executed automatically whenever a user or API call validates an observation against the affected concept. The Velocity context exposes $patient (the Person / Patient object), $obs (the Obs object), and $fn (the ConceptReferenceRangeUtility instance with access to the full OpenMRS service layer). This vulnerability is fixed in 2.7.9 and 2.8.6.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Control of Generation of Code

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.

How developers prevent this class of flaw

  • Refactor your program so that you do not have to dynamically generate code.
  • Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
  • Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

More Improper Control of Generation of Code vulnerabilities (CWE-94)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in openmrs-core

All openmrs-core vulnerabilities

Recent Improper Control of Generation of Code vulnerabilities

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