Vulnerability in Red Hat Ansible Automation Platform 2

CVE-2026-125063

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.

Vulnerability class: ReDoS (Regular Expression Denial of Service)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-125063?
CVE-2026-125063 is a medium-severity vulnerability in Red Hat Ansible Automation Platform 2, classified under Inefficient Regular Expression Complexity. CVSS score: 4.3/10. Published 2026-11-09.
How severe is CVE-2026-125063?
Medium severity. CVSS v3 base score is 4.3 out of 10.