High severity · published Sep 15, 2026
CVE-2026-91778
In affected versions of Octopus Server, users with certain scoped permission sets could execute arbitrary scripts on a worker (including the Octopus Server built-in worker)
7.2
CVSS
0.4%
EPSS
No
On KEV
Description
In affected versions of Octopus Server, users with certain scoped permission sets could execute arbitrary scripts on a worker (including the Octopus Server built-in worker). Incorrect permission validation during script execution would allow the script to execute without the user possessing the required authorisation.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OS
Octopus Server · Octopus Deploy
2019.0.0 before 2026.1.11725; 2026.2.0 before 2026.2.13344; 2026.3.0 before 2026.3.11816 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-91778
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-91778
advisories.octopus.com
https://advisories.octopus.com/post/2026/sa2026-08
More from Octopus Server
9.8
CVE-2022-2572
In affected versions of Octopus Server where access is managed by an external authentication provider, it was possible that the API key/keys of a disabled/deleted user were still…
9.8
CVE-2022-2778
In affected versions of Octopus Deploy it is possible to bypass rate limiting on login using null bytes
9.1
CVE-2026-0704
In affected version of Octopus Deploy it was possible to remove files and/or contents of files on the host using an API endpoint
9.1
CVE-2022-2782
In affected versions of Octopus Server it is possible for a session token to be valid indefinitely due to improper validation of the session token parameters
8.7
CVE-2026-116870
In affected versions of Octopus Server, OIDC token issuer validation was performed inconsistently