CVE-2026-27197 is a critical-severity (CVSS 9.1) Improper Authentication vulnerability in sentry. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
Sentry: Improper Authentication on SAML SSO process allows user identity linking
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27197.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
sentryReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A critical vulnerability was discovered in the SAML SSO implementation of Sentry. It was reported to us via our private bug bounty program.
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.
For self-hosted users, you are only vulnerable if the following conditions are met:
- You have more than one organization configured (SENTRY_SINGLE_ORGANIZATION = False).
- A malicious user has existing access and permissions to modify SSO settings for another organization in your multo-organization instance.
Patches
- Sentry SaaS: The fix was deployed on February 18, 2026. No action is required.
- Self-Hosted Sentry: If only a single organization is allowed (SENTRY_SINGLE_ORGANIZATION = True), then no action is needed. We recommend upgrading to version 26.2.0 or higher.
Workarounds
User account-based two-factor authentication prevents 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.
You can manage your two-factor authentication settings on your Account Settings > Security page. For step-by-step details, please see our helpdesk article.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | sentry | ≥ 21.12.0 | No fix |
Affected Products
sentrysentryDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sentry, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of sentry for CVE-2026-27197. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2026-27197 in your dependencies?
Find it across PyPI, including transitive dependencies.