CVE-2025-277738.6HighCWE-347

CVE-2025-27773: SimpleSAMLphp SAML2 library has incorrect signature verification for HTTP-Redirect binding

simplesamlphp · saml2

Affected: simplesamlphp saml2 · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.4%probability of exploitation in the next 30 days

36th percentile

050100

Higher than 36% of scored CVEs

8.6HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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 products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

simplesamlphp · saml2< 4.17.0; >= 5.0.0-alpha.1, < 5.0.0-alpha.20

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Improper Verification of Cryptographic Signature · Cryptography
Vendor: simplesamlphp
Published: March 2025
Band: Unlikely (under 1%), March 2025

CoverageNo articles yet

No CyberSIXT article names CVE-2025-27773 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.