A flaw was found in Ansible Tower when running Openshift. Tower runs a memcached, which is accessed via TCP. An attacker can take advantage of writing a playbook polluting this cache, causing a denial of service attack. This attack would not completely stop the service, but in the worst-case scenario, it can reduce the Tower performance, for which memcached is designed. Theoretically, more sophisticated attacks can be performed by manipulating and crafting the cache, as Tower relies on memcached as a place to pull out setting values. Confidential and sensitive data stored in memcached should not be pulled, as this information is encrypted. This flaw affects Ansible Tower versions before 3.6.4, Ansible Tower versions before 3.5.6 and Ansible Tower versions before 3.4.6.
CVSS v4.0 Metrics
Exploitability
Attack VectorLocal
ComplexityLow
RequirementsPresent
PrivilegesLow
User InteractionNone
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityLow
IntegrityNone
AvailabilityLow
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | PoC | E: U→P | 0.4 → 1.1 |
| 2026-07-21 | nvd | AV: P→L, AC: H→L, PR: H→L, UI: A→N, VC: N→L, VA: N→L | 0.0 → 0.4 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| n/a | Tower | ansible_tower 3.6.4, ansible_tower 3.5.6, ansible_tower 3.4.6 |
| redhat | ansible_tower | ≥ 3.5.0, < 3.5.6 |
| redhat | ansible_tower | ≥ 3.6.0, < 3.6.4 |
| redhat | ansible_tower | < 3.4.6 |
Published: 2021-05-27
