CVE-2026-4881Network attack vector

Authenticated server changes via missing API authorization

Published Jun 4, 2026 · Updated Jun 4, 2026

Broken access control in affected Octopus Deploy Octopus Server releases allows remote authenticated users to make server-level changes through its API. An undisclosed API endpoint performs the requested change without enforcing the caller's permissions and then returns an error. Any authenticated account can reach the flaw, but the vendor does not identify the endpoint or exact change; published metrics bound the consequence to a service interrupt.

CVSS severity6.0
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Broken access control in affected Octopus Deploy Octopus Server releases allows remote authenticated users to make server-level changes through its API. An undisclosed API endpoint performs the requested change without enforcing the caller's permissions and then returns an error. Any authenticated account can reach the flaw, but the vendor does not identify the endpoint or exact change; published metrics bound the consequence to a service interrupt.

The record

CVE
CVE-2026-4881
Published
Jun 4, 2026
Updated
Jun 4, 2026
Vendor
Octopus Deploy
Product
Octopus Server
Classifications
CWE-862, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 4, 2026Record 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=2023.0.0 <2025.4.10523
  2. Affected versionversion=2025.4.0 <2025.4.10545
  3. Affected versionversion=2026.1.0 <2026.1.11313

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Octopus Deploy · Octopus Serverversion=2023.0.0 <2025.4.10523; version=2025.4.0 <2025.4.10545; version=2026.1.0 <2026.1.11313

Published CVSS scores

6.0Octopus DeployCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
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 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-862Missing Authorization
T1210Exploitation of Remote Services

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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