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OpenID Connect nonce generated but never validated — ID token replay attack

Moderate severity GitHub Reviewed Published Apr 22, 2026 in roadiz/core-bundle-dev-app • Updated Apr 29, 2026

Package

composer roadiz/openid (Composer)

Affected versions

>= 2.7.0, < 2.7.18
>= 2.6.0, < 2.6.31
>= 2.5.0, < 2.5.45
< 2.3.43

Patched versions

2.7.18
2.6.31
2.5.45
2.3.43

Description

Summary

The roadiz/openid package generates an OIDC nonce in OAuth2LinkGenerator::generate() and includes it in the authorization request sent to the identity provider, but never stores it and never validates it on the callback. The OpenIdJwtConfigurationFactory validation chain does not include a nonce constraint, and OpenIdAuthenticator::authenticate() never checks the nonce claim in the returned ID token against a stored value.

Details

In src/OAuth2LinkGenerator.php, a nonce is created and sent to the IdP:

'nonce' => $this->tokenGenerator->generateToken(),

However, this value is neither stored in session, cache, nor any other persistent store.

In src/OpenIdJwtConfigurationFactory.php, the JWT validation constraints are:

  • LooseValidAt (expiry)
  • PermittedFor (audience)
  • IssuedBy (issuer)
  • HostedDomain (optional)
  • UserInfoEndpoint (optional)

No nonce constraint is present.

In src/Authentication/OpenIdAuthenticator.php, the authenticate() method validates the state CSRF token correctly (fixed in v2.7.10), but never retrieves a stored nonce or compares it against the nonce claim in the ID token.

PoC

  1. Obtain a valid ID token from a legitimate OIDC flow for a target user (e.g. via network interception, browser history leak, or referrer header exposure on a non-HTTPS redirect).
  2. Replay the ID token: Since the nonce in the token is never cross-checked against a client-stored value, the token passes all validation constraints as long as it has not expired.
  3. Result: An attacker can authenticate as the victim within the ID token's validity window.

Additionally, in an authorization code flow with multiple concurrent sessions, a malicious IdP or a compromised token endpoint could inject a token with a mismatched nonce, and the application would accept it silently.

Impact

  • ID token replay attacks: Valid but intercepted tokens can be reused for authentication within their validity period.
  • Token injection attacks: A malicious or compromised identity provider can inject tokens across sessions without detection.
  • Affects any Roadiz application using the roadiz/openid package with OpenID Connect SSO.

The OIDC Core 1.0 specification (Section 3.1.3.7) explicitly requires clients to verify the nonce claim if it was present in the authorization request.

References

@ambroisemaupate ambroisemaupate published to roadiz/core-bundle-dev-app Apr 22, 2026
Published to the GitHub Advisory Database Apr 29, 2026
Reviewed Apr 29, 2026
Last updated Apr 29, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User interaction None
Vulnerable System Impact Metrics
Confidentiality None
Integrity High
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

EPSS score

Weaknesses

Insufficient Verification of Data Authenticity

The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. Learn more on MITRE.

CVE ID

CVE-2026-42206

GHSA ID

GHSA-3gx8-q682-38mx

Source code

Credits

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