How to fix CVE-2025-27773?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

Is PHP affected by CVE-2025-27773?

Organizations using SimpleSAMLphp SAML2 library face significant risk from CVE-2025-27773, a signature bypass vulnerability rated CVSS 8.6. Successful exploitation could significantly impact the confidentiality, integrity, or availability of affected systems.

PHP CVE-2025-27773

HIGH

Improper Verification of Cryptographic Signature (CWE-347)

2025-03-11 [email protected]

GHSA-46r4-f8gj-xg56

PHP

8.6

CVSS 3.1

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

High

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 19:52 vuln.today

CVE Published

Mar 11, 2025 - 19:15 nvd

HIGH 8.6

DescriptionNVD

The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message. Versions 4.17.0 and 5.0.0-alpha.20 contain a fix for the issue.

AnalysisAI

SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. versions up to 4.17.0 is affected by improper verification of cryptographic signature (CVSS 8.6).

Technical ContextAI

This vulnerability (CWE-347: Improper Verification of Cryptographic Signature) affects SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality.. The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message. Versions 4.17.0 and 5.0.0-alpha.20 contain a fix for the issue.

Affected ProductsAI

Product: SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality.. Versions: up to 4.17.0.

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

CVE-2025-27773 vulnerability details – vuln.today

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PHP CVE-2025-27773

CVSS VectorNVD

Lifecycle Timeline

DescriptionNVD

AnalysisAI

Technical ContextAI

Affected ProductsAI

RemediationAI

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External POC / Exploit Code