Mage OSS: Authentication bypass via unknown OAuth provider in session creation

Summary

Mage OSS up to and including 0.9.80 keeps creating sessions when an unknown OAuth provider is requested. The request-supplied email is then used for user lookup, account creation and session issuance without token verification. An unauthenticated remote attacker can therefore log in as existing users or create new accounts, and reach features such as version control commands, the file explorer and the built-in terminal. The attack needs only network access to the Mage service, and the CVSS base score is 9.8 (critical).

Affected

• Mage OSS (mage-ai) 0 to 0.9.80
• All builds before commit 76c4f46

Fixed in

• Commit 76c4f46 (PR #6204, merged 16 October 2026) rejects unverified OAuth identities
• Released version: Unknown. PyPI 0.9.80 predates the fix; check the Mage releases for a later version that contains 76c4f46.

Workaround

• Do not expose Mage directly to the internet; restrict access to the service port (6789 by default) to trusted networks
• Place Mage behind a VPN or an authenticating reverse proxy
• Monitor POST /api/sessions requests for unknown OAuth provider values and unexpected account creation

Exploitation

• A public proof-of-concept repository exists (murrez/CVE-2026-111823), so exploit code is available.
• CISA SSVC lists exploitation as none and automatable as yes.
• Exploitation in the wild is not confirmed; no CISA KEV listing was found in the sources.
• Sources conflict on preconditions: some say user authentication must be enabled, VulDB says no authentication is needed.

Our recommendation

• Inventory all Mage OSS instances and their versions or commit hashes.
• Remove direct internet exposure and restrict access to VPN or trusted networks now.
• Update to a release that includes commit 76c4f46 or later as soon as it is available, and build from the fixed commit if needed.
• Review logs for POST /api/sessions requests with unknown providers and for unexpected user accounts.
• Recheck the NVD and CISA KEV entries, since the NVD status is Deferred.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

Links to third-party sites, not checked by us – exploit code can contain malware. Only use it in isolated test environments.

• Proof of concept on GitHub (1 repositories) iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).
  murrez/CVE-2026-111823

Research sources

• Mage PR #6204: Reject unverified OAuth session identities github.com
• Commit 76c4f46 diff for PR #6204 github.com
• Mage PR #6205: Harden version control command execution github.com
• Public proof-of-concept repository (murrez/CVE-2026-111823) github.com
• CVE-2026-111823 CNA record (Vulners) vulners.com
• VulDB entry 421535 vuldb.com
• Mage API reference: sessions overview docs.mage.ai

Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 30 Oct 2026, 17:34.