CVE-2023-25816Public exploitNetwork attack vector

Service degradation via unbounded password-reset processing

Published Feb 24, 2023 · Updated Mar 10, 2025

Uncontrolled resource consumption in Nextcloud Server 25.0.0 through 25.0.2 allows remote authenticated users to degrade service. LostController::setPassword accepted an arbitrarily long password and passed it into resource-intensive password validation without a length bound. A valid password-reset token and user interaction are required; successful requests consume excess resources and reduce server availability.

CVSS severity3.5
Low
EPSS probability1.37%
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 degrade service. LostController::setPassword accepted an arbitrarily long password and passed it into resource-intensive password validation without a length bound. A valid password-reset token and user interaction are required; successful requests consume excess resources and reduce server availability.

The record

CVE
CVE-2023-25816
Published
Feb 24, 2023
Updated
Mar 10, 2025
Vendor
Nextcloud GmbH
Product
Security Advisories
Classifications
CWE-400, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 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

3.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/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 exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

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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