CVE-2023-48302Network attack vector

Self-XSS via plaintext paste markup rendering

Published Nov 21, 2023 · Updated Aug 2, 2024

Cross-site scripting in the Text app in Nextcloud Server and Enterprise Server allows remote authenticated users to render crafted HTML. The Text editor treats clipboard content from a Ctrl+Shift+V plaintext paste as renderable markup instead of literal text. The trigger requires a logged-in user to paste attacker-supplied content into Text; no cross-user consequence is documented.

CVSS severity3.5
Low
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in the Text app in Nextcloud Server and Enterprise Server allows remote authenticated users to render crafted HTML. The Text editor treats clipboard content from a Ctrl+Shift+V plaintext paste as renderable markup instead of literal text. The trigger requires a logged-in user to paste attacker-supplied content into Text; no cross-user consequence is documented.

The record

CVE
CVE-2023-48302
Published
Nov 21, 2023
Updated
Aug 2, 2024
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-79, T1204
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 21, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record 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=>= 25.0.0, < 25.0.13
  2. Affected versionversion=>= 26.0.0, < 26.0.8
  3. Affected versionversion=>= 27.0.0, < 27.1.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=>= 25.0.0, < 25.0.13; version=>= 26.0.0, < 26.0.8; version=>= 27.0.0, < 27.1.3

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204User Execution

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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