CVE-2026-27823Network attack vector

Remote code execution via header.inc.php overwrite

Published Jul 20, 2026 · Updated Jul 20, 2026

Code injection in EGroupware 23.1.20260131 and earlier and 26.2.20260216 and earlier allows remote authenticated users to execute PHP code. The SmallPartMediaRecorder::ajax_upload() method trusts a request-supplied participant_role for its teacher check and uses video_type to traverse paths and overwrite header.inc.php after importexport_export_ui::download discloses the original file. Authentication is normally required; enabled self-registration removes that gate, and execution follows a server restart or OPcache expiration.

CVSS severity9.3
Critical
EPSS probability1.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in EGroupware 23.1.20260131 and earlier and 26.2.20260216 and earlier allows remote authenticated users to execute PHP code. The SmallPartMediaRecorder::ajax_upload() method trusts a request-supplied participant_role for its teacher check and uses video_type to traverse paths and overwrite header.inc.php after importexport_export_ui::download discloses the original file. Authentication is normally required; enabled self-registration removes that gate, and execution follows a server restart or OPcache expiration.

The record

CVE
CVE-2026-27823
Published
Jul 20, 2026
Updated
Jul 20, 2026
Vendor
EGroupware GmbH
Product
EGroupware
Classifications
CWE-94, CWE-639, CWE-22, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 23.1.20260131
  2. Affected versionversion=<= 26.2.20260216

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EGroupware GmbH · EGroupwareversion=<= 23.1.20260131; version=<= 26.2.20260216

Published CVSS scores

9.3GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
9.1GitLab Advisory DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-639Authorization Bypass Through User-Controlled Key
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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