CVE-2023-28644Network attack vector

Service interruption via unrestricted reference downloads

Published Mar 30, 2023 · Updated Feb 11, 2025

Uncontrolled resource consumption in Nextcloud Server 25.0.0 through 25.0.2 allows remote authenticated users to interrupt service via Talk messages. The OpenGraph link provider issues a full GET for each reference URL and reads the response for up to 10 seconds without first enforcing content type or a 5 MB size limit. A logged-in user must supply the URL, and user interaction is required; large or slow responses can temporarily exhaust disk space and saturate server bandwidth.

CVSS severity5.7
Medium
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Nextcloud Server 25.0.0 through 25.0.2 allows remote authenticated users to interrupt service via Talk messages. The OpenGraph link provider issues a full GET for each reference URL and reads the response for up to 10 seconds without first enforcing content type or a 5 MB size limit. A logged-in user must supply the URL, and user interaction is required; large or slow responses can temporarily exhaust disk space and saturate server bandwidth.

The record

CVE
CVE-2023-28644
Published
Mar 30, 2023
Updated
Feb 11, 2025
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 11, 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=>= 25.0.0, < 25.0.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Security Advisoriesversion=>= 25.0.0, < 25.0.3

Published CVSS scores

5.7GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

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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