CVE-2026-122220
highWPO365 | LOGIN (wpo365-login) plugin before version 45.2 contains an authentication bypass by capture-replay vulnerability caused by a non-functional anti-repl…
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://plugins.trac.wordpress.org/changeset/3783469/ disclosure@vulncheck.com
- https://wordpress.org/plugins/wpo365-login/#developers disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/wpo365-login-before-saml-replay-protection-bypass disclosure@vulncheck.com

