CVE-2026-27197 in sentry
Summary
by MITRE • 02/21/2026
Sentry is a developer-first error tracking and performance monitoring tool. Versions 21.12.0 through 26.1.0 have a critical vulnerability in its SAML SSO implementation which allows an attacker to take over any user account by using a malicious SAML Identity Provider and another organization on the same Sentry instance. Self-hosted users are only at risk if the following criteria is met: ore than one organizations are configured (SENTRY_SINGLE_ORGANIZATION = True), or malicious user has existing access and permissions to modify SSO settings for another organization in a multo-organization instance. This issue has been fixed in version 26.2.0. To workaround this issue, implement user account-based two-factor authentication to prevent an attacker from being able to complete authentication with a victim's user account. Organization administrators cannot do this on a user's behalf, this requires individual users to ensure 2FA has been enabled for their account.
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability identified as CVE-2026-27197 affects Sentry, a popular error tracking and performance monitoring platform widely used by developers and organizations for application monitoring and debugging. This critical flaw resides within the Security Assertion Markup Language (SAML) Single Sign-On (SSO) implementation of Sentry versions 21.12.0 through 26.1.0, creating a significant security risk for self-hosted deployments. The vulnerability stems from improper validation of SAML assertions and cross-organization authentication flows, allowing attackers to exploit the system's SAML configuration to gain unauthorized access to user accounts across different organizations within the same Sentry instance.
The technical flaw manifests when an attacker constructs a malicious SAML Identity Provider that can manipulate authentication responses to bypass normal access controls. This vulnerability specifically targets multi-organization Sentry deployments where the SENTRY_SINGLE_ORGANIZATION setting is disabled, enabling cross-organization authentication attacks. The exploit requires either the presence of multiple organizations within the same Sentry instance or an attacker who already possesses sufficient privileges to modify SSO settings for another organization. This creates a privilege escalation scenario where unauthorized individuals can leverage existing SAML configurations to impersonate legitimate users across different organizational boundaries. The vulnerability aligns with CWE-287 (Improper Authentication) and represents a serious breakdown in the principle of least privilege within the SAML authentication flow.
The operational impact of this vulnerability extends beyond simple unauthorized access, creating a potential for widespread account compromise within affected organizations. Attackers can leverage this flaw to gain persistent access to user accounts, potentially leading to data breaches, system manipulation, and unauthorized code deployments. The risk is particularly severe for organizations with multiple teams or departments sharing a single Sentry instance, as a successful exploitation could allow attackers to move laterally between organizational units. This vulnerability also undermines the trust model that SAML SSO is designed to provide, as it allows attackers to bypass the intended authentication boundaries between different organizational entities within the same platform instance. The attack vector specifically targets the SAML assertion processing pipeline, where the system fails to properly validate that the authenticated user belongs to the organization they claim to represent, creating a path for cross-organizational privilege escalation.
Organizations affected by this vulnerability must immediately upgrade to Sentry version 26.2.0 or later to receive the official patch addressing the SAML assertion validation issues. The fix implements proper cross-organization boundary checking and ensures that SAML assertions are validated against the correct organizational context before granting access. In the interim, organizations should implement user account-based two-factor authentication as a compensating control, as this requires individual users to enable 2FA on their accounts to prevent successful exploitation. This mitigation approach aligns with the principle of defense in depth and addresses the vulnerability at the account level rather than the system level. However, it's important to note that organization administrators cannot enforce 2FA on behalf of users, as this requires individual user participation and awareness to properly secure their accounts. The vulnerability also highlights the importance of proper SAML configuration management and the need for organizations to regularly audit their authentication settings to prevent similar issues in the future. This weakness demonstrates the critical importance of maintaining proper authentication boundaries in multi-tenant systems and underscores the need for robust session management and user context validation in SAML implementations. The attack pattern associated with this vulnerability follows the MITRE ATT&CK technique T1566 (Phishing for Information) and T1078 (Valid Accounts) as attackers would need to first establish access to the system and then leverage the SAML vulnerability to escalate privileges, making it a particularly dangerous flaw for organizations relying on SAML-based authentication.