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SentryApplication

CVE-2026-42354

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-08
Fix available
A fix is available. Upgrade to 26.4.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Sentry is an error tracking and performance monitoring tool. From version 21.12.0 to before version 26.4.1, a critical vulnerability was discovered in the SAML SSO implementation of Sentry. The vulnerability allows an attacker to take over any user account by using a malicious SAML Identity Provider and another organization on the same Sentry instance. The victim email address must be known in order to exploit this vulnerability. This issue has been patched in version 26.4.1.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A critical account takeover vulnerability exists in Sentry's SAML SSO implementation affecting versions 21.12.0 through 26.4.0. An attacker with a malicious SAML Identity Provider and knowledge of a victim's email address can take over any user account by exploiting the trust relationship between organizations on the same Sentry instance.

MitigationUpgrade Sentry to version 26.4.1 or later to apply the security patch. Review SAML SSO configurations and monitor for unauthorized account access attempts.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
SentryApplication
Affected:>= 21.12.0, < 26.4.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Sentry installation version
    Locate the Sentry installation and retrieve its version number (typically found in UI under /admin/ or via sentry --version CLI, or in package/config files)
    Affected if The installed version is >= 21.12.0 and < 26.4.1
  2. Confirm SAML SSO is configured
    Access Sentry admin settings and inspect Authentication/SSO configuration to verify if SAML Identity Provider is linked
    Affected if SAML SSO is enabled and at least one SAML IdP is configured in the Sentry instance
  3. Check for multiple organizations
    List all organizations hosted on the same Sentry instance (via Sentry UI organization switcher, API, or database query on the organization table)
    Affected if Two or more organizations exist on the same Sentry instance and share the same authentication backend
  4. Review recent SAML authentication logs
    Examine Sentry audit logs and authentication logs for SAML login events, looking for unexpected IdP assertions or login patterns
    Affected if Unusual SAML authentication activity is present, especially involving organizations the reviewer does not manage

The environment is affected if running a Sentry version between 21.12.0 and 26.4.1 inclusive with SAML SSO enabled and multiple organizations present on the same instance.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 26.4.1 or later
Fixed in 26.4.1
Vendor patch github.com →
Interim mitigation

Upgrade Sentry to version 26.4.1 or later to apply the security patch. Review SAML SSO configurations and monitor for unauthorized account access attempts.

Recommended fix High confidence

26.4.1

  1. 1. Backup your Sentry installation and database before proceeding with the upgrade.
  2. 2. Determine your current Sentry version by checking the installation or running `sentry --version`.
  3. 3. Upgrade Sentry to version 26.4.1 or later using your deployment method (e.g., pip install sentry==26.4.1, Docker image tag, or package manager).
  4. 4. Restart all Sentry services after the upgrade.
  5. 5. Verify the upgrade was successful by checking the Sentry version and testing SAML SSO functionality.
  6. 6. Review SAML SSO configuration to ensure no unauthorized Identity Providers have been added.
Caveat Standard Sentry upgrade considerations apply; review the 26.4.1 release notes for any migration steps or configuration changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Sentry Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42354 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data