groupoffice: Improper Control of Generation of Code
CVE-2026-63011 is a critical-severity improper control of generation of code vulnerability in groupoffice from Intermesh, with a CVSS 4.0 base score of 9.4 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. Affected groupoffice versions: < 6.8.167; < 25.0.102; < 26.0.27. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of groupoffice you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Intermesh | groupoffice | < 6.8.167; < 25.0.102; < 26.0.27 | Not 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.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- HighSerious loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- HighSerious loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- HighSerious loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (github.com).
Official description
Group-Office is an enterprise customer relationship management and groupware tool. Prior to versions 6.8.167, 25.0.102, and 26.0.27, the Contact/labels JMAP endpoint in GroupOffice accepts a fully attacker-controlled template string (tpl parameter) that is passed without restriction to TemplateParser::parse(). When the template contains an [assign] block whose expression includes a {{...}} variable reference, the engine calls eval() on the expanded expression after running it through a validateExpression() guard. The guard double-quotes unrecognized tokens, but PHP 7+ allows a string enclosed in parentheses to be invoked as a function ("system")("id") is valid PHP and calls system("id"). A single authenticated HTTP request is sufficient to execute arbitrary OS commands as the web server user (www-data). This issue has been patched in versions 6.8.167, 25.0.102, and 26.0.27.
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
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in groupoffice
- 8.7 High severity
- 9.9 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Recent Improper Control of Generation of Code vulnerabilities
- 9.9 Critical severity
- 9.9 Critical severity
- 9.9 Critical severity
- 8.1 High severity
- 8.2 High severity
- 7.2 High severity
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