sentry: Improper Authentication
CVE-2026-27197 is a critical-severity improper authentication vulnerability in sentry from Getsentry, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected sentry versions: >= 21.12.0, < 26.2.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of sentry you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (github.com).
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in sentry
- 7.6 High severity
- 7.7 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.1 Critical severity
Recent Improper Authentication vulnerabilities
- 8.1 High severity
- 9.4 Critical severity
- 10.0 Critical severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
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