CVE-2026-67990

Disabling CSRF in Basecamp Upright Proxy Controllers Enables Unauthorized Operations

Published Aug 13, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
basecamp/upright at commit efe4f2e5254ac6e57e45d2261804cca74dbbca3f disables Rails CSRF protection for its Alertmanager and Prometheus proxy controllers. An unauthenticated attacker can induce a logged-in user's browser to submit requests that are forwarded to enabled upstream write or management endpoints, such as creating an Alertmanager silence or requesting a Prometheus reload. The final impact depends on the APIs enabled by the upstream services.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Title Basecamp Upright Allows Unauthenticated CSRF to Write to Upstream Alertmanager and Prometheus Endpoints Disabling CSRF in Basecamp Upright Proxy Controllers Enables Unauthorized Operations
Type Values Removed Values Added
Title Basecamp Upright Allows Unauthenticated CSRF to Write to Upstream Alertmanager and Prometheus Endpoints
Type Values Removed Values Added
Weaknesses CWE-352
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description basecamp/upright at commit efe4f2e5254ac6e57e45d2261804cca74dbbca3f disables Rails CSRF protection for its Alertmanager and Prometheus proxy controllers. An unauthenticated attacker can induce a logged-in user's browser to submit requests that are forwarded to enabled upstream write or management endpoints, such as creating an Alertmanager silence or requesting a Prometheus reload. The final impact depends on the APIs enabled by the upstream services.
References

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Aug 13, 2026, 3:45 PM
Reserved
Jul 30, 2026, 12:00 AM
Status
Deferred
Published
Aug 13, 2026, 2:17 PM
Modified
Sep 8, 2026, 7:42 PM