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Ethyca Fides has a Privacy Request Identity Verification Bypass Vulnerability via Duplicate Detection

Moderate severity GitHub Reviewed Published Apr 27, 2026 in ethyca/fides • Updated May 13, 2026

Package

pip ethyca-fides (pip)

Affected versions

>= 2.75.0, < 2.83.2

Patched versions

2.83.2

Description

Summary

Fides deployments that enable both subject identity verification and duplicate privacy request detection are affected by a vulnerability in which an administrator can approve a privacy request whose identity was never verified. For erasure policies, this can result in unauthorized deletion of a data subject's records across every integration configured in the affected deployment.

A related lower-severity denial-of-service issue, in which an unauthenticated attacker could prevent a legitimate data subject from completing their own privacy requests, is also patched in the fix for this vulnerability.

Am I affected?

This vulnerability only affects deployments that use Fides's privacy request (data subject request) features, also known collectively as "Lethe". Deployments that do not submit, process, or manage privacy requests through Fides are not affected.

Within deployments that do use privacy request features, your deployment is affected if both of the following settings are effectively set to true:

  • subject_identity_verification_required
  • privacy_request_duplicate_detection.enabled

Both settings default to false.

Each setting can be configured in multiple places. If the same setting is configured in more than one place, Fides resolves conflicts in the following precedence order, highest priority first:

  1. Admin UI / configuration API - stored in the application database and applied at runtime
  2. Environment variables - read at webserver startup
  3. fides.toml - read at webserver startup
  4. Default value - used if none of the above set the value

To determine whether your deployment is affected, check each setting in every location that applies to your configuration management.

subject_identity_verification_required

  • fides.toml: under the [execution] section as subject_identity_verification_required = true
  • Environment variable: FIDES__EXECUTION__SUBJECT_IDENTITY_VERIFICATION_REQUIRED=true
  • No Admin UI control - this setting is not exposed through the Admin UI and cannot be set via the configuration API

privacy_request_duplicate_detection.enabled

  • fides.toml: under the [privacy_request_duplicate_detection] section as enabled = true
  • Environment variable: FIDES__PRIVACY_REQUEST_DUPLICATE_DETECTION__ENABLED=true
  • Admin UI: Settings → Privacy requests → Duplicate detection, via the "Enable duplicate detection" toggle. The toggle reflects only values set through the Admin UI or configuration API. A value set via fides.toml or environment variable will not appear here.

GHSA - Duplicate Detection Enabled

The "Enable duplicate detection" toggle when it's enabled, under Settings → Privacy requests in the Admin UI.

Details

When duplicate detection classifies a privacy request as a duplicate before its identity has been verified, the administrative interface presents that request with Approve, Deny, and Delete options. An administrator performing routine duplicate request triage may approve such a request without realising the identity was never verified. The request is then processed as if verification had succeeded.

An attacker exploits this by submitting two privacy requests using a target's email address, never completing the OTP verification. The second request is classified as a duplicate and becomes approvable through the administrative interface.

The fix for this vulnerability also patches a lower-severity issue, present in versions 2.82.0 through 2.83.1, in which a legitimate data subject could not complete identity verification on a privacy request that had been classified as a duplicate, allowing an unauthenticated attacker to block that data subject from exercising their privacy rights through the affected deployment.

Impact

An unauthenticated attacker who knows a target's email address and can reach the public Privacy Center can cause an erasure privacy request to be approved by an administrator and processed without identity verification. The result is unauthorized deletion of the data subject's records across every integration configured in the affected deployment. Effects may be permanent and may cascade into downstream systems.

Access privacy requests are a less meaningful vector: the resulting access package is delivered to the data subject's registered email address, not to the attacker, so the attacker does not gain the data. The request still represents unauthorized processing.

Patches

The vulnerabilities have been patched in Fides OSS version 2.83.2. Users are advised to upgrade to this version or later to secure their systems against these threats.

Fides Enterprise (fidesplus) version 2.83.2 contains the same patch.

Workarounds

Disable duplicate detection by setting privacy_request_duplicate_detection.enabled to false. This can be changed under Settings → Privacy Requests → Duplicate detection in the Admin UI). This fully mitigates the vulnerability and is the recommended interim workaround for deployments that cannot immediately upgrade.

GHSA - Disable Duplicate Detection

The "Enable duplicate detection" toggle when it's disabled, under Settings → Privacy requests in the Admin UI.

Administrators of deployments that must retain duplicate detection should deny or delete, rather than approve, any privacy request whose identity has not been verified. This reduces the likelihood of exploitation but relies on administrator vigilance during each triage action.

GHSA - Admin Approval of Unverified Privacy Request

An administrator's view when approving an unverified privacy request in the Admin UI.

Severity

This vulnerability has been assigned a severity of MEDIUM.

The rating reflects the fact that exploitation requires an administrator to approve the malicious request. An attacker alone cannot cause a privacy request to be processed. The administrative interface understates the verification state of a duplicate-classified request, which increases the likelihood of inadvertent approval during routine triage, but without administrator user interaction the vulnerability is not exploitable.

The related denial-of-service issue addressed in the same patch is also rated medium-severity in isolation and does not raise the overall severity of this advisory.

References

References

@daveqnet daveqnet published to ethyca/fides Apr 27, 2026
Published to the GitHub Advisory Database May 5, 2026
Reviewed May 5, 2026
Published by the National Vulnerability Database May 12, 2026
Last updated May 13, 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 None
User interaction Active
Vulnerable System Impact Metrics
Confidentiality None
Integrity Low
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity High
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:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:H/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(23rd percentile)

Weaknesses

Authentication Bypass Using an Alternate Path or Channel

The product requires authentication, but the product has an alternate path or channel that does not require authentication. Learn more on MITRE.

Missing Authentication for Critical Function

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. Learn more on MITRE.

Improper Enforcement of Behavioral Workflow

The product supports a session in which more than one behavior must be performed by an actor, but it does not properly ensure that the actor performs the behaviors in the required sequence. Learn more on MITRE.

CVE ID

CVE-2026-42303

GHSA ID

GHSA-qx5f-ghc2-7g5c

Source code

Credits

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