codemeter-runtime: Use of Externally-Controlled Format String
CVE-2026-81574 is a high-severity use of externally-controlled format string vulnerability in codemeter-runtime from Wibu-systems-ag, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 9.10, 8.41a as the first without the flaw, so updating codemeter-runtime to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.43% 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 codemeter-runtime to 9.10 or 8.41a, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Wibu-systems-ag | codemeter-runtime | 9.00 up to, but not including, 9.10; 8.00 up to, but not including, 8.41a; 7.00 | 9.10, 8.41a |
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
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H. Scored by CNA.
Official description
In CodeMeter Runtime before versions 8.41a and 9.10, the logger does not sanitize input strings in certain cases, allowing an attacker to inject printf-style format specifiers. This can be used to reliably crash CodeMeter and disclose sensitive information such as process memory and stack canaries. The attack works locally, for example by using cmu --set-proxy to set the proxy value, and remotely when combined with CVE-2026-81573 by setting General.ProxyServer and then triggering this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Externally-Controlled Format String
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
How developers prevent this class of flaw
- Choose a language that is not subject to this flaw.
- Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings.
- Run compilers and linkers with high warning levels, since they may detect incorrect usage.
More Use of Externally-Controlled Format String vulnerabilities (CWE-134)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in codemeter-runtime
- 7.7 High severity
- 7.5 High severity
- 8.6 High severity
- 7.8 High severity
Recent Use of Externally-Controlled Format String vulnerabilities
- 9.8 Critical severity
- 7.1 High severity
- 8.7 High severity
- 7.2 High severity
- 8.1 High severity
- 8.1 High severity
Spotted an error? Tell us.