CyberSecBulletin
CVE-2026-101169NVD status: Awaiting Analysis

Octopus Server: Deserialization of Untrusted Data

Published Updated By the CyberSecBulletin desk

CVE-2026-101169 is a high-severity deserialization of untrusted data 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 2026.1.11781, 2026.2.13441, 2026.3.15829 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 0.35% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Octopus Server to 2026.1.11781 or 2026.2.13441 or 2026.3.15829, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
Octopus DeployOctopus Server2019.4.1 up to, but not including, 2026.1.11781; 2026.2.0 up to, but not including, 2026.2.13441; 2026.3.0 up to, but not including, 2026.3.158292026.1.11781, 2026.2.13441, 2026.3.15829

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, an authenticated user with permissions to edit an Environment or Project can set specifically crafted JSON content for the object. Insecure deserialization of this content allows the user to execute arbitrary code in the Octopus Server process.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Deserialization of Untrusted Data

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

How developers prevent this class of flaw

  • 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.
  • When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
  • Explicitly define a final object() to prevent deserialization.

More Deserialization of Untrusted Data vulnerabilities (CWE-502)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).

References

Other vulnerabilities in Octopus Server

All Octopus Server vulnerabilities

Recent Deserialization of Untrusted Data vulnerabilities

Spotted an error? Tell us.