Collabora Online, Built-in CODE Server: attackers can run commands on it
OFFICIAL NAME: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability
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TECHNICAL SUMMARY Collabora Collabora Online – Built-in CODE Server when used within the NextCloud platform contains an OS command injection vulnerability that allows for remote code execution when the CODE server isn't running.
WHY THIS VERDICT Attacks are confirmed. The vulnerability is 28 days old, so many systems are likely still unpatched. Ready-made attack tools are public. The severity score is critical (9.2). The exploit prediction score is 73%.
WHY IT RANKS HERE Exploitation is confirmed by an authoritative source. Ready-made attack tools are public. The confirmation is 19 days old.
- HIGHEST CONFIRMED RUNG
- EXPLOITED
- CISA KEV
- LISTED
- EXPLOIT CODE
- READY TO USE
How far has it climbed?
01 TALK
■ CONFIRMEDNEWEST EVIDENCE · 3 INDEPENDENT SOURCESCVE-2026-110447 discussed publicly (CIRCL sighting). CVE-2026-110447 discussed publicly (CIRCL sighting).
- SRC: CIRCL Vulnerability-Lookup sightings: CVE-2026-110447 discussed publicly (CIRCL sighting) · NOV 5
- SRC: Security Affairs: U.S. CISA adds Collabora Online flaw to its Known Exploited Vulnerabilities catalog · OCT 24
- SRC: The Hacker News: CISA Flags Two Actively Exploited Critical Flaws in Collabora Online and Arista VeloCloud · OCT 23
02 EXPOSED
□ NOT TRACKED YETNO SOURCE FOR THIS STEP YETWe have no source that counts exposed systems yet. Internet scan data needs a partnership we do not have. No evidence here does not mean nothing is exposed.
03 TRIED
■ CONFIRMEDNEWEST EVIDENCE · 3 INDEPENDENT SOURCESAttacks that worked are confirmed (step 4), so attempts count as confirmed too.
- SRC: CIRCL Vulnerability-Lookup sightings: Exploitation of CVE-2026-110447 reported (CIRCL sighting) · OCT 23
- SRC: CISA Known Exploited Vulnerabilities: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability · OCT 22
- SRC: CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-110447 as actively exploited · OCT 13
04 EXPLOITED
■ CONFIRMEDNEWEST EVIDENCE · 3 INDEPENDENT SOURCESExploitation of CVE-2026-110447 reported (CIRCL sighting). Collabora Collabora Online – Built-in CODE Server when used within the NextCloud platform contains an OS command injection vulnerability that allows for remote code execution when the CODE server isn't running.
- SRC: CIRCL Vulnerability-Lookup sightings: Exploitation of CVE-2026-110447 reported (CIRCL sighting) · OCT 23
- SRC: CISA Known Exploited Vulnerabilities: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability · OCT 22
- SRC: CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-110447 as actively exploited · OCT 13
05 DAMAGE
□ NOT TRACKED YETNO SOURCE FOR THIS STEP YETBreach notices and filings rarely name the flaw that was used, so we cannot link them to this event yet. No evidence here does not mean no harm.
When each thing happened
- DISCLOSED
- EXPLOIT CODE PUBLIC
- FIRST ATTACK REPORT
- CISA KEV LISTING
- US FEDERAL DEADLINE
THE FIX
CISA's instruction: apply the vendor's fix, or stop using the product if no fix exists. The deadline CISA set for US federal agencies, Oct 26, 2026, has passed. It is a US government deadline; use it as a guide.
Questions to ask this week
- Do we run Collabora Online, Built-in CODE Server? If yes, is it patched or cut off from the internet?
- Who owns fixing it, and by what date?
- Have we checked for signs of attack since the first report, not just since the patch?
How it unfolded
- Attack activity. OCT 13, 2026CISA Vulnrichment marks CVE-2026-110447 as actively exploited
- OCT 14, 20261 public GitHub repository claims a proof of concept for CVE-2026-110447
- Attack activity. OCT 22, 2026Collabora Online – Built-in CODE Server OS Command Injection Vulnerability
- Attack activity. OCT 23, 2026Exploitation of CVE-2026-110447 reported (CIRCL sighting)
- OCT 23, 2026CISA Flags Two Actively Exploited Critical Flaws in Collabora Online and Arista VeloCloud
- OCT 23, 2026CVE-2026-110447 discussed publicly (CIRCL sighting) (19 reports, latest NOV 5)
- OCT 24, 2026U.S. CISA adds Collabora Online flaw to its Known Exploited Vulnerabilities catalog
- OCT 28, 2026Vulnerability CVE-2026-110447 confirmed by a researcher (CIRCL sighting)
SOURCES
- [1] nuclei-templates: Nuclei scan template: Collabora Built-in CODE Server < 26.4.303 - OS Command Injection, OCT 28
- [2] CIRCL Vulnerability-Lookup sightings: CVE-2026-110447 discussed publicly (CIRCL sighting), NOV 5
- [3] CIRCL Vulnerability-Lookup sightings: Vulnerability CVE-2026-110447 confirmed by a researcher (CIRCL sighting), OCT 28
- [4] Security Affairs: U.S. CISA adds Collabora Online flaw to its Known Exploited Vulnerabilities catalog, OCT 24
- [5] The Hacker News: CISA Flags Two Actively Exploited Critical Flaws in Collabora Online and Arista VeloCloud, OCT 23
- [6] CIRCL Vulnerability-Lookup sightings: Exploitation of CVE-2026-110447 reported (CIRCL sighting), OCT 23
- [7] CISA Known Exploited Vulnerabilities: Collabora Online – Built-in CODE Server OS Command Injection Vulnerability, OCT 22
- [8] PoC-in-GitHub: 1 public GitHub repository claims a proof of concept for CVE-2026-110447, OCT 14
- [9] CVE List V5 and CISA Vulnrichment: CISA Vulnrichment marks CVE-2026-110447 as actively exploited, OCT 13
- [10] CIRCL Vulnerability-Lookup sightings: 18 more reports