Octopus Server: Improperly Controlled Modification of Dynamically-Determined Object Attributes
CVE-2026-116835 is a high-severity improperly controlled modification of dynamically-determined object attributes vulnerability in Octopus Server from Octopus Deploy, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 2026.2.13503, 2026.3.15894 as the first without the flaw, so updating Octopus Server to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Octopus Server to 2026.2.13503 or 2026.3.15894, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Octopus Deploy | Octopus Server | 2025.3.11571 up to, but not including, 2026.2.13503; 2026.3.0 up to, but not including, 2026.3.15894 | 2026.2.13503, 2026.3.15894 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (octopus.com).
Official description
In affected versions of Octopus Server, insufficient validation of custom claims on OIDC accounts allowed a user with permission to edit accounts to cause Octopus Server to issue signed OIDC tokens that impersonate a different project. This could grant access to external systems, such as cloud providers or other Octopus instances, that trust that project's identity.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improperly Controlled Modification of Dynamically-Determined Object Attributes
The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.
How developers prevent this class of flaw
- If available, use features of the language or framework that allow specification of allowlists of attributes or fields that are allowed to be modified. If possible, prefer allowlists over denylists. For applications written with Ruby on Rails, use the attr_accessible (allowlist) or attr_protected (denylist) macros in each class that may be used in mass assignment.
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- For any externally-influenced input, check the input against an allowlist of internal object attributes or fields that are allowed to be modified.
Timeline
- CVE record published.
References
Other references
Other vulnerabilities in Octopus Server
- 8.7 High severity
- 8.7 High severity
- 7.1 High severity
- 7.7 High severity
- 8.7 High severity
- 7.7 High severity
Recent Improperly Controlled Modification of Dynamically-Determined Object Attributes vulnerabilities
- 7.5 High severity
- 8.1 High severity
- 9.6 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.1 High severity
Spotted an error? Tell us.