# CVE-2026-63011: GroupOffice Vulnerable to RCE in TemplateParser eval() via Contact/labels

Status: published. Published: 2026-11-10. Updated: 2026-11-10.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Intermesh / groupoffice: < 6.8.167 (affected); < 25.0.102 (affected); < 26.0.27 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 4.0: 9.4 (critical); 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; source: CNA: GitHub_M

- CVSS 4.0: 9.4 (critical); 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; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-94, CWE-95, CWE-184

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/Intermesh/groupoffice/security/advisories/GHSA-4m9w-3p93-6cwx (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/Intermesh/groupoffice/releases/tag/v25.0.102 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/Intermesh/groupoffice/releases/tag/v26.0.27 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/Intermesh/groupoffice/releases/tag/v6.8.167 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/Intermesh/groupoffice/releases/tag/v25.0.102 (security-advisories@github.com)

- https://github.com/Intermesh/groupoffice/releases/tag/v26.0.27 (security-advisories@github.com)

- https://github.com/Intermesh/groupoffice/releases/tag/v6.8.167 (security-advisories@github.com)

- https://github.com/Intermesh/groupoffice/security/advisories/GHSA-4m9w-3p93-6cwx (security-advisories@github.com)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-63011; retrieved 2026-11-10; source updated 2026-11-10

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-63011; retrieved 2026-11-10; source updated 2026-11-10

Revision: 680425b02cf6a220e5b0a22673fe2e40b7b4b3050f30ec0ab0d824aac3af31b8

Canonical: https://y2.dev/cve/CVE-2026-63011

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