What’s Vulnerable › Vulnerabilities

CVE-2026-49454: Relyra SAML SignatureValue not cryptographically verified -> authentication bypass

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-18 · updated 2026-10-26
• Weakness: CWE-287

Description

Relyra is a strict-by-default SAML 2.0 Service Provider library for Elixir and Phoenix. Versions 1.0.0 and 1.1.0 accept forged SAML signatures because SignatureValue was not cryptographically verified before the library returned a successful authentication result. The XMLDSig trust boundary was incomplete as :public_key.verify over the exclusive-C14N canonicalized SignedInfo was not performed against the configured IdP certificate's public key, DigestValue was not recomputed over the canonicalized referenced element, and canonicalize/2 remained an unused passthrough in the signature-verification path. The result was a structure-only acceptance path where document shape and trust-source rejection could succeed without proving the signature bytes. A forged SignatureValue carrying an attacker-controlled NameID could be accepted as {:ok}. This issue has been fixed in version 1.2.0.

Affected products

• szTheory relyra: from 1.0.0, < 1.2.0

References

• https://github.com/szTheory/relyra/commit/2e456897af3158c175bb490ce7fc51d6241c8922
• https://github.com/szTheory/relyra/commit/8910200
• https://github.com/szTheory/relyra/security/advisories/GHSA-jv46-xfwm-36j7

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