CVE-2023-48314VulnerabilityPublished 1 Dec 2023Updated 3 Jun 2025

CVE-2023-48314: CollaboraOnline online · Cross-site Scripting

Affects CollaboraOnline onlineSource CVE Database V5

Not known to be exploited · CVSS 7.1 High : upgrade to 23.5.403 soon.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 23.5.403

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Dec 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade collaboraonline/online to 23.5.403.

Affected software

Product	Affected	Fixed in
GitHubcollaboraonline/online`pkg:github/collaboraonline/online`Other threats	Affected <23.5.403	Fixed in 23.5.403

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Immediate upgrade of Collabora Online Built-in CODE Server to version 23.5.403 or later is essential to remediate the vulnerability. 2. Review and restrict access to the proxy.php endpoint to trusted users and networks where possible, using network segmentation and firewall rules. 3. Implement Content Security Policy (CSP) headers to reduce the impact of potential XSS attacks by restricting the execution of unauthorized scripts. 4. Enhance user awareness training focused on phishing and social engineering tactics to reduce the likelihood of users triggering the vulnerability. 5. Monitor Nextcloud and Collabora Online logs for unusual activity or access patterns that could indicate exploitation attempts. 6. Consider deploying web application firewalls (WAFs) with rules targeting XSS payloads to provide an additional layer of defense. 7. Regularly audit and update all integrated components and dependencies to ensure no residual vulnerabilities remain. 8. For organizations unable to immediately patch, isolate the affected services and limit user access until the update can be applied.

Description

Collabora Online is a collaborative online office suite based on LibreOffice technology. Users of Nextcloud with Collabora Online Built-in CODE Server app can be vulnerable to attack via proxy.php. This vulnerability has been fixed in Collabora Online - Built-in CODE Server (richdocumentscode) release 23.5.403. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Impact

For European organizations, the impact of CVE-2023-48314 can be significant, especially for those relying on Nextcloud integrated with Collabora Online for document collaboration and productivity. Successful exploitation could lead to unauthorized access to sensitive documents, leakage of confidential information, and compromise of user sessions. This is particularly critical for sectors handling sensitive personal data or intellectual property, such as finance, healthcare, government, and legal services. The vulnerability’s ability to affect confidentiality, integrity, and availability means attackers could manipulate documents, disrupt collaboration workflows, or use the platform as a pivot point for broader network attacks. Given the widespread adoption of Nextcloud and Collabora Online in Europe as open-source alternatives to proprietary office suites, many organizations could be exposed if they have not applied the patch. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits rapidly once the vulnerability is public. The requirement for user interaction means phishing or social engineering could be used to trigger the attack, increasing the risk in environments with less mature security awareness.

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #1OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation · Architecture and Design
Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages.
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide…
OWASP Cheat Sheets
Cross Site Scripting Prevention (opens in a new tab)
DOM based XSS Prevention (opens in a new tab)
Injection Prevention (opens in a new tab)
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
OWASP ASVS 4.0.3
V5.3.3 (opens in a new tab)
V1.5.1 (opens in a new tab)
Attack patterns
XSS Using MIME Type Mismatch (opens in a new tab)
DOM-Based XSS (opens in a new tab)
Reflected XSS (opens in a new tab)
Stored XSS (opens in a new tab)
Cross-Site Scripting (XSS) (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/CollaboraOnline/online/security/advisories/GHSA-qjrm-q4h5-v3r2 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 3 Jul 2025, 18:13 UTC

WeaknessesCWE-79

Technical details

References

Community reviews

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