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HighVulnerabilityCVE-2026-116870updated 27 Oct 2026, 12:48 UTC

Octopus Server may accept forged login tokens from untrusted identity providers

A flaw in how Octopus Server checks login tokens could let someone from an untrusted login provider sign in as a trusted automation account. The attacker would need to know some details of that account's login setup.

Official, 3 sources
SeverityHighCVSS 8.7 of 10
Being exploited?UnclearNo reports either way yet
Fix available?UnclearNo fixed version published in the sources yet
How sure is this?Official, 3 sourcesBacked by an official source

How the attack works simplified

  1. 1Attacker sets up issuerRuns a non-legitimate OIDC issuer
  2. 2Forged token issuedToken claims a trusted service account
  3. 3Inconsistent validationIssuer check is skipped in some paths
  4. 4Login acceptedToken treated as trusted service account
  5. ResultAttacker acts as the service account

What happened

In affected Octopus Server versions, OIDC token issuer validation is applied inconsistently, so a token from a suitably configured non-legitimate issuer can be accepted as belonging to a service account from a trusted issuer.

Why it is dangerous: A successful attacker could act with the permissions of a service account, which may be used for deployments, so organisations that run Octopus Server with OIDC service accounts are at risk.

Are you affected?

You are affected if you run Octopus Server with at least one service account that has an OIDC identity configured.

Octopus Server (affected versions not specified in the provided material)

What to do

  1. Identify whether your Octopus Server has any service accounts with OIDC identities configured
  2. Check the Octopus Deploy vendor advisory (GHSA-j58f-w66m-94wj) for the fixed version and update Octopus Server
  3. Review OIDC service account identities and remove any that are unused
  4. Review audit logs for unexpected service account activity

Timeline

  1. 27 Oct 2026, 11:17 UTC
    Publicly disclosed
  2. 27 Oct 2026, 11:17 UTC
    Reported by NVD · NVD
  3. 27 Oct 2026, 11:17 UTC
    Picked up by Zero Radar
  4. 27 Oct 2026, 12:43 UTC
    CERT-Bund (BSI) reported on it · CERT-Bund (BSI)
  5. 27 Oct 2026, 12:48 UTC
    GitHub Advisory reported on it · GitHub Advisory

Sources 3 reports, oldest first

Official vendor, government CERT or advisory database

Technical details

ID
CVE-2026-116870 · GHSA-j58f-w66m-94wj
CVSS
8.7 / 10
EPSS
0.2% chance of exploitation within 30 days
Disclosed
27 Oct 2026, 11:17 UTC
On Zero Radar
27 Oct 2026, 11:17 UTC (0 min after disclosure)
Last change
27 Oct 2026, 12:48 UTC

The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works

Octopus Server may accept forged login tokens from untrusted identity providers · Zero Radar