CVE-2026-110447

Status: DeferredCritical (9.2)—PoC

Severity9.2Critical · CVSS 4.0

Exploitation probability1.23 %higher than 68% of CVEs

Active exploitationNonot in the CISA catalog

Public exploitAvailableProof of concept on GitHub (unverified)

Collabora Online Built-in CODE Server before 26.4.303 (richdocumentscode), a Nextcloud app, allows remote code execution, as exploited in the wild in September and October 2026, a different vulnerability than CVE-2025-66208. This is an OS command injection in proxy.php when the CODE server isn't running (e.g., the product was recently restarted). The vulnerability is not present in standalone Collabora Online servers; only this deployment with CODE Server is affected.

CVSS

Base score: 9.2
Version: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/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

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 1.23 %
Percentile among all scored CVEs: 68
Score date: 10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Public exploits

Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.

Proof of concept on GitHub (unverified) · List of proofs of concept on GitHub

⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.

Media coverage

Specialised security media that have cited this CVE:

El Hacker · Aprovechan vulnerabilidad de RCE en Collabora para instalar puertas traseras en servidores Nextcloud (10/17/2026)
BleepingComputer · Hackers exploit Collabora RCE flaw to backdoor Nextcloud servers (10/15/2026)

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access95 %
Primary impactT1059 Command and Scripting Interpreterexecution85 %

Vector AV:N/PR:N/UI:N (explotación remota sin privilegios) y descripción de inyección de comandos del SO en proxy.php (CWE-78) que permite ejecución remota de código.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Privileged Account Management Vulnerability Scanning Restrict Web-Based Content Network Segmentation Limit Software Installation Limit Access to Resource Over Network

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Collabora — Richdocumentscode^AI

CWEs

CWE-78

References

Show 2 references

Raw JSON (NVD)

Show

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