Octopus Server
CVE-2021-26556
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A08:2025 - Software or Data Integrity Failures
ASVS 5.0
V13 - Configuration Search path verification
|
| Impact | CVSS score of 7.8 (HIGH). Attack characteristics: local attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | Successful exploitation could compromise the high-severity affected system. |
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Alert meAnalysisAI
When Octopus Server is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user using DLL side-loading to gain privileged access. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
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Technical ContextAI · show details
This vulnerability is classified under CWE-426. When Octopus Server is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user using DLL side-loading to gain privileged access. Affected products include: Octopus Octopus Deploy, Octopus Octopus Server.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
When Octopus Server is installed using a custom folder location, folder ACLs are not set correctly and could lead to an unprivileged user using DLL side-loading to gain privileged access.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
More in Octopus Server
View allIn Octopus Deploy 2018.8.0 through 2018.9.x before 2018.9.1, an authenticated user with permission to modify deployment
In Octopus Deploy 2019.1.0 through 2019.3.1 and 2019.4.0 through 2019.4.5, an authenticated user with the VariableViewUn
Server-level configuration changes can be made by any authenticated low-privilege user in Octopus Server through a speci
In affected versions of Octopus Server where access is managed by an external authentication provider, it was possible t
In affected versions of Octopus Deploy it is possible to bypass rate limiting on login using null bytes. Rated critical
In Octopus Deploy 2018.4.4 through 2018.5.1, Octopus variables that are sourced from the target do not have sensitive va
Path traversal in Octopus Deploy allows removing files and file contents on the host through API manipulation. Enables d
In affected versions of Octopus Server it is possible for a session token to be valid indefinitely due to improper valid
Path traversal in Octopus Server allows an authenticated low-privilege user to overwrite arbitrary files on the server f
Authenticated remote code execution in Octopus Server allows any user whose role grants permission to edit an Environmen
Privilege escalation in Octopus Server lets an authenticated user who already holds permission to modify roles weaken a
Incorrect authorization in Octopus Server causes the platform to evaluate multiple scoped permission assignments incorre
NVD
CVE.org
EPSS
GitHub PoC
Exploit-DB