# CVE-2026-42354: Sentry account takeover via SAML SSO identity spoofing

Source: https://junglewise.ai/threats/cve-2026-42354-sentry-account-takeover-via-saml-sso-identity-spoofing  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-08. Updated: 2026-05-18  
License: CC BY 4.0 with a link back

CVE-2026-42354 · Severity: critical · CVSS 9.1 · Published 2026-05-08

Sentry is an error tracking and performance monitoring platform used by developers to monitor application health. A critical vulnerability in its login system allows an attacker to take over any user account if they know the victim's email address. This could lead to unauthorized access to sensitive source code, error logs, and customer data, potentially compromising the entire development pipeline.

Technologies: [sentry (PyPI)](https://junglewise.ai/threats/technologies/pypi-sentry). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-42354 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42354 being exploited in the wild.

**How severe is CVE-2026-42354?** Critical severity, with a CVSS score of 9.1, published 8 May 2026.

**Which products and versions are affected?** sentry (PyPI) ECOSYSTEM:introduced=21.12.0,fixed=26.4.1.

**Is there a fix for CVE-2026-42354?** Yes. sentry (PyPI): upgrade to 26.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-42354 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-42354?** Check whether you run sentry (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- sentry (PyPI): upgrade to 26.4.1 or later

  ```sh
  pip install "sentry>=26.4.1"
  ```


## Technical details

An authentication bypass vulnerability (CWE-290) exists in Sentry's SAML SSO implementation due to improper identity linking during the SSO setup process. In multi-organization instances where SENTRY_SINGLE_ORGANIZATION is disabled, an attacker with administrative control over one organization can use a malicious SAML Identity Provider to assert the email address of a victim in a different organization. Because the system failed to properly pin the SSO setup identity to the authenticated session, it allowed the attacker to link their malicious IdP to the victim's account. Successful exploitation requires the attacker to know the victim's email address and results in full account takeover. The issue is resolved in version 26.4.1 by ensuring the IdP assertion email is overridden by the authenticated user's email during setup.

## Affected products

- Sentry Sentry >= 21.12.0, < 26.4.1

## Identifiers

- CVE-2026-42354
- GHSA-rcmw-7mc7-3rj7
- PYSEC-2026-534

## Timeline

- 2026-04-22: patched: Fix merged and version 26.4.1 released
- 2026-04-22: advisory: GitHub Security Advisory published
- 2026-05-08: disclosed: CVE published to NVD

## References

- [https://github.com/getsentry/sentry/commit/0c67558ae7fe08738912d4c5233b53ead048da3b](https://github.com/getsentry/sentry/commit/0c67558ae7fe08738912d4c5233b53ead048da3b)
- [https://github.com/getsentry/sentry/pull/113720](https://github.com/getsentry/sentry/pull/113720)
- [https://github.com/getsentry/sentry/releases/tag/26.4.1](https://github.com/getsentry/sentry/releases/tag/26.4.1)
- [https://github.com/getsentry/sentry/security/advisories/GHSA-rcmw-7mc7-3rj7](https://github.com/getsentry/sentry/security/advisories/GHSA-rcmw-7mc7-3rj7)

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