CVE-2023-48314Network attack vector

Reflected XSS via unescaped proxy request URL

Published Dec 1, 2023 · Updated Jun 3, 2025

Reflected XSS in Collabora Online before 23.5.403 allows remote attackers to execute script in a user's browser through proxy.php. The proxy.php error path inserts a malformed request query into an HTML error response without neutralizing markup. A victim must open an attacker-crafted URL; the script then runs in the Collabora and Nextcloud origin with that user's browser privileges.

CVSS severity7.1
High
EPSS probability0.41%
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 before 23.5.403 allows remote attackers to execute script in a user's browser through proxy.php. The proxy.php error path inserts a malformed request query into an HTML error response without neutralizing markup. A victim must open an attacker-crafted URL; the script then runs in the Collabora and Nextcloud origin with that user's browser privileges.

The record

CVE
CVE-2023-48314
Published
Dec 1, 2023
Updated
Jun 3, 2025
Vendor
Collabora Productivity
Product
Collabora Online
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2025Record 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=< 23.5.403

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Collabora Productivity · Collabora Onlineversion=< 23.5.403

Published CVSS scores

7.1GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

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.

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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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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