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PatchSiren cyber security CVE debrief

CVE-2026-104759 wpo365 CVE debrief

The WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN) plugin for WordPress is vulnerable to Authentication Bypass via OIDC Nonce Replay in all versions up to, and including, 44.1. This vulnerability allows unauthenticated attackers to replay a previously-issued, valid id_token and authenticate as any WordPress user, including administrators, resulting in full site takeover when the use_id_token_parser_v2 plugin option is enabled.

Vendor
wpo365
Product
WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN)
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-10
Original CVE updated
2026-10-10
Advisory published
2026-10-10
Advisory updated
2026-10-10

Who should care

WordPress administrators and defenders who use the WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN) plugin should assess exposure and verify the use_id_token_parser_v2 plugin option.

Why it matters

Defenders should prioritize verifying the use_id_token_parser_v2 plugin option and checking for valid id_token values to prevent authentication bypass. This vulnerability allows unauthenticated attackers to replay a previously-issued, valid id_token and authenticate as any WordPress user, including administrators, resulting in full site takeover.

  • Unauthenticated attackers can replay valid id_token values to authenticate as any WordPress user
  • Full site takeover is possible when the use_id_token_parser_v2 plugin option is enabled

Technical summary

The WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN) plugin for WordPress is vulnerable to Authentication Bypass via OIDC Nonce Replay in all versions up to, and including, 44.1. This is due to Id_Token_Service_Deprecated::process_openidconnect_token() using the incompatible WordPress core wp_verify_nonce() function to validate a nonce produced by Nonce_Service::create_nonce().

Defensive priority

Defenders should prioritize verifying the use_id_token_parser_v2 plugin option and checking for valid id_token values to prevent authentication bypass.

Recommended defensive actions

  • Verify the use_id_token_parser_v2 plugin option is disabled
  • Check id_token values for validity before processing
  • Monitor for suspicious authentication attempts
  • Implement additional logging and monitoring to detect potential authentication bypass attempts
  • Review and update incident response plans to address potential authentication bypass incidents
  • Conduct a thorough review of the plugin's configuration and settings to ensure secure deployment
  • Perform a vulnerability scan to identify any other potential vulnerabilities in the plugin or related systems

Evidence notes

The vulnerability exists due to the Id_Token_Service_Deprecated::process_openidconnect_token() function using the incompatible WordPress core wp_verify_nonce() function to validate a nonce produced by Nonce_Service::create_nonce().

Sources and references

Verified primary and authoritative sources

  • CVE-2026-104759 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-104759

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-104759 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-104759

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • WPO365 | SEAMLESS WORDPRESS + MICROSOFT INTEGRATION (WPO365 | LOGIN) <= 44.1 - Unauthenticated A

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/104xxx/CVE-2026-104759.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/browser/wpo365-login/tags/44.1/Services/Id_Token_Service_Deprecated.php

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/browser/wpo365-login/tags/44.1/Services/Router_Service.php

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/browser/wpo365-login/tags/44.1/Services/Id_Token_Service.php

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/browser/wpo365-login/tags/44.1/Services/Nonce_Service.php

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://plugins.trac.wordpress.org/changeset/3727410/wpo365-login

    Supplemental source

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.