CyberSecBulletin
CVE-2026-22208NVD status: Deferred

OpenS100: Exposed Dangerous Method or Function

CVE-2026-22208 is a critical-severity exposed dangerous method or function vulnerability in OpenS100 from OpenS100 Project, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 753cf294434e8d3961f20a567c4d99151e3b530d as the first without the flaw, so updating OpenS100 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.1% chance of exploitation within 30 days, higher than 66% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update OpenS100 to 753cf294434e8d3961f20a567c4d99151e3b530d or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
  3. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
OpenS100 ProjectOpenS100before 753cf294434e8d3961f20a567c4d99151e3b530d753cf294434e8d3961f20a567c4d99151e3b530d

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
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
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:N/UI:R/S:C/C:H/I:H/A:H. Scored by CNA (vulncheck.com).

Scoring systemScoreSeverityScored by
CVSS 4.09.4CriticalCNA (vulncheck.com)
CVSS 3.19.6CriticalCNA (vulncheck.com)

Official description

OpenS100 (the reference implementation S-100 viewer) prior to commit 753cf29 contains a remote code execution vulnerability via an unrestricted Lua interpreter. The Portrayal Engine initializes Lua using luaL_openlibs() without sandboxing or capability restrictions, exposing standard libraries such as 'os' and 'io' to untrusted portrayal catalogues. An attacker can provide a malicious S-100 portrayal catalogue containing Lua scripts that execute arbitrary commands with the privileges of the OpenS100 process when a user imports the catalogue and loads a chart.

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

The underlying weakness: Exposed Dangerous Method or Function

The product provides an Applications Programming Interface (API) or similar interface for interaction with external actors, but the interface includes a dangerous method or function that is not properly restricted.

How developers prevent this class of flaw

  • If you must expose a method, make sure to perform input validation on all arguments, limit access to authorized parties, and protect against all possible vulnerabilities.
  • Identify all exposed functionality. Explicitly list all functionality that must be exposed to some user or set of users. Identify which functionality may be: accessible to all users restricted to a small set of privileged users prevented from being directly accessible at all Ensure that the implemented code follows these expectations. This includes setting the appropriate access modifiers where applicable (public, private, protected, etc.) or not marking ActiveX controls safe-for-scripting.

More Exposed Dangerous Method or Function vulnerabilities (CWE-749)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in OpenS100

All OpenS100 vulnerabilities

Recent Exposed Dangerous Method or Function vulnerabilities

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