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

> Attackers can bypass authentication in Relyra SAML library by forging signatures, allowing unauthorized access and account takeover.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Jun 2026
- **Updated:** 22 Jun 2026
- **Also known as:** GHSA-jv46-xfwm-36j7

## What is CVE-2026-49454?

CVE-2026-49454 is a critical authentication bypass vulnerability in szTheory relyra, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-49454?

2 open source packages ship an affected version, including relyra.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `relyra` | Hex | From 1.0.0 | 1.2.0 |
| `relyra` | Hex | From 1.0.0 | 1.2.0 |

## How do I fix CVE-2026-49454?

Upgrade relyra to 1.2.0 or later.

## Is CVE-2026-49454 being exploited?

There is no known exploitation of CVE-2026-49454 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-49454 and fix it if it is affected.

What it is: CVE-2026-49454 is a critical authentication bypass vulnerability in szTheory relyra, published on 18 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-49454 in the wild and no public exploit code.

Affected packages and fixed versions:
- relyra (Hex): affected from 1.0.0; fixed in 1.2.0
- relyra (Hex): affected from 1.0.0; fixed in 1.2.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-49454/ (Markdown: https://insights.sbomify.com/CVE-2026-49454/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-49454
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-49454
- OSV: https://osv.dev/vulnerability/CVE-2026-49454

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-49454/
Summaries are generated and may contain mistakes; the official description above is the record.