CVE-2026-63011: Group-Office (critical)

Summary

Group-Office, an enterprise customer relationship management and groupware tool, has a flaw in its Contact/labels template handling that lets a logged-in attacker run arbitrary operating system commands on the server as the web server user. The attacker can reach it remotely over the network with only low-privilege login and no user interaction.

Read the original 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.

cve.now Index

18Pcve.now Index 18 of 100 · methodology v3 · provisional

Exploitation0/40No signal
Exposure8/25Specific setups only, reachable over the network
Reach?/20Unknown. No tracked technology or package matched
Severity10/10CVSS 9.4, total technical impact per CISA
No patch0/5No signal

What would change the score

Would score about 68 if added to CISA KEV
Would score about 63 if CISA's SSVC rates exploitation active
Would score about 25 if CISA's SSVC rates it automatable

How the score works · Rankings

What to do

Check whether your setup matches what the bug needs.
Contact/labels JMAP endpoint accepts an attacker-supplied tpl template parameter Template must contain an [assign] block whose expression includes a {{...}} variable reference Affected versions are 26.0.26, 25.0.101 and 6.8.166 and earlier in those branches
Upgrade to a fixed version: 6.8.167, 25.0.102, 26.0.27.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by CVE-2026-63011 (GroupOffice Vulnerable to RCE in TemplateParser eval() via Contact/labels), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-63011 (entry last updated 2026-11-10):
Affected:
- Intermesh groupoffice: fixed in 6.8.167; fixed in 25.0.102; fixed in 26.0.27
Fixed versions: 6.8.167, 25.0.102, 26.0.27.
Conditions (all must be true for the bug to be hit):
- Contact/labels JMAP endpoint accepts an attacker-supplied tpl template parameter (source: https://github.com/Intermesh/groupoffice/security/advisories/GHSA-4m9w-3p93-6cwx)
- Template must contain an [assign] block whose expression includes a {{...}} variable reference (source: https://github.com/Intermesh/groupoffice/security/advisories/GHSA-4m9w-3p93-6cwx)
- Affected versions are 26.0.26, 25.0.101 and 6.8.166 and earlier in those branches (source: https://github.com/Intermesh/groupoffice/security/advisories/GHSA-4m9w-3p93-6cwx)
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
Attacker needs: network access, low-privilege login, no user action.
CISA KEV: CVE-2026-63011 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-63011 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/Intermesh/groupoffice/security/advisories/GHSA-4m9w-3p93-6cwx
- https://github.com/Intermesh/groupoffice/releases/tag/v25.0.102
- https://github.com/Intermesh/groupoffice/releases/tag/v26.0.27
- https://github.com/Intermesh/groupoffice/releases/tag/v6.8.167
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Entry: https://cve.now/CVE-2026-63011
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-63011.

Timeline

Nov 10, 2026, 4:35 PM UTCCVE published
Nov 10, 2026, 4:45 PM UTCFirst seen by cve.now
Nov 10, 2026, 4:59 PM UTCPosted on X by cve.now
Nov 10, 2026, 9:04 PM UTCCISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
Nov 10, 2026, 9:05 PM UTCRecord last updated

Affected versions

Intermesh groupoffice
fixed in 6.8.167; fixed in 25.0.102; fixed in 26.0.27

Evidence 6

Vendor advisory · 1

Establishes: Affected and fixed versions.

Advisory
GitHub · Intermesh/groupoffice · Advisory GHSA-4m9w-3p93-6cwx

CVE record · 2

Establishes: The identifier and description.

Record
CVE List · CVE-2026-63011
Record
NVD · CVE-2026-63011

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

Questions about CVE-2026-63011

Is CVE-2026-63011 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data

What does this mean?

The Contact/labels JMAP endpoint accepts a template from the request and passes it to TemplateParser, which runs eval() on an [assign] expression containing a {{...}} variable reference. This lets arbitrary OS commands run as the web server user (www-data).Source: github.com

Which versions are affected by CVE-2026-63011?

groupoffice: before 6.8.167; before 25.0.102; before 26.0.27.Source: cve.now feed data

Am I affected, and how do I check?

Versions 26.0.26, 25.0.101 and 6.8.166 and earlier in those branches are affected, when the template contains an [assign] block with a {{...}} variable reference. To check an installation, compare its GroupOffice version number against these versions.Source: github.com

How do I fix CVE-2026-63011?

Upgrade to the fixed release for the installed branch: 6.8.167, 25.0.102 or 26.0.27.Source: github.com

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