9.1
CRITICAL CVSS 4.0
CVE-2026-122220
WPO365 LOGIN before 45.2 SAML Replay Protection Bypass
Description

WPO365 | LOGIN (wpo365-login) plugin before version 45.2 contains an authentication bypass by capture-replay vulnerability caused by a non-functional anti-replay check in Saml2_Service::check_message_id(), which never persists processed SAML message IDs to the wpo365_saml_message_ids transient due to a logic error that returns before saving. Attackers who capture a validly-signed SAMLResponse can replay it to the ACS endpoint repeatedly within its assertion validity window to log in as the victim, including administrators, without detection since the duplicate message ID check never triggers.

INFO

Published Date :

Nov. 4, 2026, 8:19 p.m.

Last Modified :

Nov. 4, 2026, 8:19 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-122220 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 HIGH [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Update the WPO365 | LOGIN plugin to version 45.2 or later to fix an authentication bypass vulnerability.
  • Update the WPO365 | LOGIN plugin to version 45.2.
  • Verify the anti-replay check is functional.
  • Monitor for suspicious login activity.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-122220.

URL Resource
https://plugins.trac.wordpress.org/changeset/3783469/
https://wordpress.org/plugins/wpo365-login/#developers
https://www.vulncheck.com/advisories/wpo365-login-before-saml-replay-protection-bypass
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-122220 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-122220 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-122220 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Nov. 04, 2026

    Action Type Old Value New Value
    Added Description WPO365 | LOGIN (wpo365-login) plugin before version 45.2 contains an authentication bypass by capture-replay vulnerability caused by a non-functional anti-replay check in Saml2_Service::check_message_id(), which never persists processed SAML message IDs to the wpo365_saml_message_ids transient due to a logic error that returns before saving. Attackers who capture a validly-signed SAMLResponse can replay it to the ACS endpoint repeatedly within its assertion validity window to log in as the victim, including administrators, without detection since the duplicate message ID check never triggers.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/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
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
    Added CWE CWE-294
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/122xxx/CVE-2026-122220.json">CVE-2026-122220</a>
    Added Reference https://plugins.trac.wordpress.org/changeset/3783469/
    Added Reference https://wordpress.org/plugins/wpo365-login/#developers
    Added Reference https://www.vulncheck.com/advisories/wpo365-login-before-saml-replay-protection-bypass
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.