Description
Impact:
A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service.
Patches:
Fixed in version 8.4.0.
Workarounds:
Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.
Metrics
CVSS 3.1 7.5/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| path-to-regexp | path-to-regexp | >= 8.0.0, < 8.4.0 |
| Red Hat | Cryostat 4 on RHEL 9 | — |
| Red Hat | Red Hat Ansible Automation Platform 2.5 for RHEL 8 | — |
| Red Hat | Red Hat Ansible Automation Platform 2.5 for RHEL 9 | — |
| Red Hat | Red Hat Ansible Automation Platform 2.6 for RHEL 9 | — |
| Red Hat | Migration Toolkit for Virtualization 2.1 | — |
| Red Hat | Migration Toolkit for Virtualization 2.9 | — |
| Red Hat | Red Hat Ansible Automation Platform 2.6 | — |
| Red Hat | Red Hat Ansible Automation Platform 2.6 | — |
| Red Hat | Red Hat Developer Hub 1.8 | — |
| Red Hat | Red Hat Developer Hub 1.9 | — |
| Red Hat | Red Hat Edge Manager 1.0 | — |
| Red Hat | Red Hat Edge Manager 1.0 | — |
| Red Hat | Red Hat Edge Manager 1.1 | — |
| Red Hat | Red Hat Edge Manager 1.1 | — |
| Red Hat | Red Hat Edge Manager 1.1 | — |
| Red Hat | Red Hat Edge Manager 1.1 | — |
| Red Hat | Red Hat Migration Toolkit for Applications 8.1 | — |
| Red Hat | Red Hat OpenShift AI 2.25 | — |
| Red Hat | Red Hat OpenShift Dev Spaces 3.27 | — |
| Red Hat | Red Hat OpenShift Dev Spaces 3.27 | — |
| Red Hat | Red Hat OpenShift distributed tracing 3.9.3 | — |
| Red Hat | Red Hat Trusted Artifact Signer 1.3 | — |
| Red Hat | Cryostat 4 | — |
| Red Hat | Logging Subsystem for Red Hat OpenShift | — |
| Red Hat | Logging Subsystem for Red Hat OpenShift | — |
| Red Hat | Logging Subsystem for Red Hat OpenShift | — |
| Red Hat | Logging Subsystem for Red Hat OpenShift | — |
| Red Hat | Logging Subsystem for Red Hat OpenShift | — |
| Red Hat | Logging Subsystem for Red Hat OpenShift | — |
| Red Hat | Multicluster Engine for Kubernetes | — |
| Red Hat | Network Observability Operator | — |
| Red Hat | OpenShift Lightspeed | — |
| Red Hat | OpenShift Lightspeed | — |
| Red Hat | OpenShift Pipelines | — |
| Red Hat | OpenShift Service Mesh 2 | — |
| Red Hat | OpenShift Service Mesh 2 | — |
| Red Hat | OpenShift Service Mesh 3 | — |
| Red Hat | OpenShift Service Mesh 3 | — |
| Red Hat | OpenShift Service Mesh 3 | — |
| Red Hat | OpenShift Service Mesh 3 | — |
| Red Hat | Red Hat Advanced Cluster Management for Kubernetes 2 | — |
| Red Hat | Red Hat Advanced Cluster Security 4 | — |
| Red Hat | Red Hat AMQ Broker 7 | — |
| Red Hat | Red Hat AMQ Broker 7 | — |
| Red Hat | Red Hat Ansible Automation Platform 2 | — |
| Red Hat | Red Hat Ansible Automation Platform 2 | — |
| Red Hat | Red Hat build of Apache Camel - HawtIO 4 | — |
| Red Hat | Red Hat build of Apicurio Registry 2 | — |
| Red Hat | Red Hat Build of Podman Desktop | — |
References
- https://cna.openjsf.org/security-advisories.htmlThird Party Advisory
- https://access.redhat.com/errata/RHSA-2026:10153
- https://access.redhat.com/errata/RHSA-2026:10172
- https://access.redhat.com/errata/RHSA-2026:10175
- https://access.redhat.com/errata/RHSA-2026:13545
- https://access.redhat.com/errata/RHSA-2026:13826
- https://access.redhat.com/errata/RHSA-2026:17789
- https://access.redhat.com/errata/RHSA-2026:19409
- https://access.redhat.com/errata/RHSA-2026:19410
- https://access.redhat.com/errata/RHSA-2026:24761
- https://access.redhat.com/errata/RHSA-2026:24762
- https://access.redhat.com/errata/RHSA-2026:24866
- https://access.redhat.com/errata/RHSA-2026:36651
- https://access.redhat.com/errata/RHSA-2026:40118
- https://access.redhat.com/errata/RHSA-2026:40945
- https://access.redhat.com/errata/RHSA-2026:50300
- https://access.redhat.com/errata/RHSA-2026:65126
- https://access.redhat.com/errata/RHSA-2026:9385
- https://access.redhat.com/errata/RHSA-2026:9742
- https://access.redhat.com/security/cve/CVE-2026-4926
- https://bugzilla.redhat.com/show_bug.cgi?id=2451867
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4926.json
Timeline
- Published
- Mar 26, 2026
- Last modified
- Sep 9, 2026
- NVD status
- Modified