Vulnerability · Published Aug 13, 2026 · Assigned by mitre
CVE-2026-67990
Medium 5.4
In plain English
A medium-severity cross-site request forgery in the at package (Ubuntu). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | at | no fix listed | UBUNTU-CVE-2026-67990 |
| Ubuntu:24.04:LTS | at | no fix listed | UBUNTU-CVE-2026-67990 |
| Ubuntu:26.04:LTS | at | no fix listed | UBUNTU-CVE-2026-67990 |
Affected products (as reported)
Weakness: CWE-352 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
References
- https://github.com/basecamp/upright
- https://github.com/basecamp/upright/blob/efe4f2e5254ac6e57e45d2261804cca74dbbca3f/app/controllers/upright/alertmanager_proxy_controller.rb#L2
- https://github.com/basecamp/upright/blob/efe4f2e5254ac6e57e45d2261804cca74dbbca3f/app/controllers/upright/prometheus_proxy_controller.rb#L2
- https://gist.github.com/Zykis1024/cec690012eecac53f408e78d2b569f06