CVE-2019-15616Network attack vector

Service interruption via unbounded remote-share HTTP requests

Published Feb 4, 2020 · Updated Aug 5, 2024

Resource-exhaustion flaw in Nextcloud Server before 17.0.0 allows remote authenticated users to interrupt service via remote shares. The federated-sharing path sends synchronous HTTP requests to a share recipient without a default timeout, allowing a stalled peer to hold a PHP worker. An authenticated account must initiate remote shares toward a server that delays responses; sustained attempts can exhaust request workers and make the web service unavailable.

CVSS severity4.3
Medium
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource-exhaustion flaw in Nextcloud Server before 17.0.0 allows remote authenticated users to interrupt service via remote shares. The federated-sharing path sends synchronous HTTP requests to a share recipient without a default timeout, allowing a stalled peer to hold a PHP worker. An authenticated account must initiate remote shares toward a server that delays responses; sustained attempts can exhaust request workers and make the web service unavailable.

The record

CVE
CVE-2019-15616
Published
Feb 4, 2020
Updated
Aug 5, 2024
Vendor
Nextcloud GmbH
Product
Nextcloud Server
Classifications
CWE-93, CWE-1088, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 4, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record 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=17.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Nextcloud GmbH · Nextcloud Serverversion=17.0.0

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:P/A:N
4.3Nextcloud GmbHCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

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-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
CWE-1088Synchronous Access of Remote Resource without Timeout
T1499Endpoint Denial of Service

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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