Vulnerability in SAML Single Sign On – SSO Login (WordPress plugin) (CVE-2026-15013)
Summary
Vulnerability in SAML Single Sign On – SSO Login (WordPress plugin) (CVE-2026-15013). Successful exploitation can lead to full system takeover. Exploitable via SignatureMethod.
Original description
The description as published by the source.
The SAML Single Sign On – SSO Login plugin for WordPress is vulnerable to Authentication Bypass via SAML Signature Algorithm Confusion in all versions up to, and including, 5.4.3. The vulnerability exists because Mo_SAML_Utilities::mo_saml_cast_key() reads the SignatureMethod Algorithm attribute directly from the attacker-controlled SAMLResponse parameter rather than enforcing the locally configured algorithm, causing the plugin to recast the IdP's RSA public key as an HMAC-SHA1 shared secret and validate the forged signature against it. This makes it possible for unauthenticated attackers to forge a SAML assertion targeting any WordPress account — including administrators — obtain valid WordPress authentication cookies, and achieve full administrator-level account takeover.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-15013 has been found in SAML Single Sign On – SSO Login (WordPress plugin).
Attackers can target a specific entry point like SignatureMethod over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "SAML Single Sign On – SSO Login (WordPress plugin) CVE-2026-15013" on the vendor's site.
CVE-2026-15013 (SAML Single Sign On – SSO Login (WordPress plugin)) — CWE-347 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: SignatureMethod / SAMLResponse
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-347) exists in SAML Single Sign On – SSO Login (WordPress plugin). Attackers reach the vulnerable code path via SignatureMethod without authentication.
Check the vendor advisory for the affected versions of SAML Single Sign On – SSO Login (WordPress plugin). Attack surface: SignatureMethod / SAMLResponse.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで SAML Single Sign On – SSO Login (WordPress plugin) を使っているサービスとバージョンを洗い出す。
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2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- web security@wordfence.com
- web security@wordfence.com
- web security@wordfence.com
- web security@wordfence.com
- web security@wordfence.com
- web security@wordfence.com
- web security@wordfence.com
- web nvd.nist.gov
- web github.com
- web seclists.org