Vulnerability · Published Jun 18, 2026 · Assigned by GitHub_M

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

Critical 9.1

In plain English

A critical-severity improper authentication in relyra from szTheory. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical

Exploit odds (30 days)0.2%top 86.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
szTheory	relyra	>= 1.0.0, < 1.2.0

Weakness: CWE-287, CWE-347 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

References

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