Skip to content
Fencer Intel
critical 9.4

CVE-2026-63011 json

GroupOffice Vulnerable to RCE in TemplateParser eval() via Contact/labels

published 4mo ago modified yesterday also EUVD-2026-121330 , GHSA-4m9w-3p93-6cwx

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository Intermesh/groupoffice. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
9.4
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

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.

Patch / fix

Is CVE-2026-63011 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
yesterday

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 9.4 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
CNA 4.0 9.4 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

Affected products

  • Intermesh groupoffice

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code
  • CWE-95 Improper Neutralization of Directives in Dynamically Evaluated Code
  • CWE-184 Incomplete List of Disallowed Inputs

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of Intermesh/groupoffice published their own advisory on GitHub. Reviewed sources take precedence over it.