CVE-2023-31145Network attack vector

Account takeover via reflected CSP-bypassing script injection

Published May 15, 2023 · Updated Jan 22, 2025

Reflected XSS in Collabora Online allows remote attackers to take over victim accounts through a crafted request executed in a browser. The vendor identifies full CSP bypass but has not disclosed the affected request parameter or the server-side reflection operation. Exploitation requires a Nextcloud installation using the recommended bundle and a victim to open attacker-controlled content; successful execution runs code in that victim's browser session.

CVSS severity4.3
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Collabora Online allows remote attackers to take over victim accounts through a crafted request executed in a browser. The vendor identifies full CSP bypass but has not disclosed the affected request parameter or the server-side reflection operation. Exploitation requires a Nextcloud installation using the recommended bundle and a victim to open attacker-controlled content; successful execution runs code in that victim's browser session.

The record

CVE
CVE-2023-31145
Published
May 15, 2023
Updated
Jan 22, 2025
Vendor
Collabora Productivity
Product
Collabora Online
Classifications
CWE-80, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 21.0.0, < 21.11.9
  2. Affected versionversion=>= 22.0.0, < 22.05.13
  3. Affected versionversion=< 6.4.27

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Collabora Productivity · Collabora Onlineversion=>= 21.0.0, < 21.11.9; version=>= 22.0.0, < 22.05.13; version=< 6.4.27

Published CVSS scores

4.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
T1189Drive-by Compromise

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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