A flaw was found in the Undertow AJP connector. Malicious requests and abrupt connection closes could be triggered by an attacker using query strings with non-RFC compliant characters resulting in a denial of service. The highest threat from this vulnerability is to system availability. This affects Undertow 2.1.5.SP1, 2.0.33.SP2, and 2.2.3.SP1.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityUnreported
Vulnerable System
ConfidentialityNone
IntegrityNone
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | nvd | AV: P→N, AC: H→L, PR: H→N, UI: A→N, VA: N→H | 0.0 → 4.6 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| n/a | Undertow | 2.0.33.SP2 |
| n/a | Undertow | 2.1.5.SP1 |
| n/a | Undertow | 2.2.3.SP1 |
| redhat | jboss_fuse | 6.0.0 |
| redhat | jboss_fuse | 7.0.0 |
| redhat | openshift_application_runtimes | All versions |
| redhat | undertow | 2.0.33 |
| redhat | undertow | 2.1.5 |
| redhat | undertow | 2.2.3 |
Published: 2021-02-23
