A flaw was found in the rrule validation of schedules in automation controller. Several non-anchored regular expressions with lazy wildcard prefixes are applied to the user-supplied rrule value; when the expected DTSTART/RRULE tokens are absent, validation time grows quadratically with the length of the value. An authenticated user can submit a large token-free rrule through the REST API, including the schedule preview endpoint, which requires no resource-level permissions; validation runs synchronously in the API web worker, so a single such request occupies a worker for an extended time and repeated requests can exhaust the web worker pool, denying access to the API and web UI while the attack is sustained. The impact is limited to availability.
Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

The schedule preview endpoint is available to any authenticated user and cannot be restricted by RBAC, so exposure can only be reduced by limiting API access to trusted users.

History

Mon, 09 Nov 2026 18:00:00 +0000

Type Values Removed Values Added
Description A flaw was found in the rrule validation of schedules in automation controller. Several non-anchored regular expressions with lazy wildcard prefixes are applied to the user-supplied rrule value; when the expected DTSTART/RRULE tokens are absent, validation time grows quadratically with the length of the value. An authenticated user can submit a large token-free rrule through the REST API, including the schedule preview endpoint, which requires no resource-level permissions; validation runs synchronously in the API web worker, so a single such request occupies a worker for an extended time and repeated requests can exhaust the web worker pool, denying access to the API and web UI while the attack is sustained. The impact is limited to availability.
Title Automation-controller: automation-controller: quadratic regex in schedule rrule validation allows an authenticated user to exhaust api web workers (denial of service)
First Time appeared Redhat
Redhat ansible Automation Platform
Weaknesses CWE-1333
CPEs cpe:/a:redhat:ansible_automation_platform:2
Vendors & Products Redhat
Redhat ansible Automation Platform
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-11-09T18:16:53.855Z

Reserved: 2026-11-09T16:37:12.862Z

Link: CVE-2026-125063

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-11-09T18:17:27.053

Modified: 2026-11-09T18:17:27.177

Link: CVE-2026-125063

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses