Traefik vulnerable to bypassing IP allow-lists via HTTP/3 early data requests in QUIC 0-RTT handshakes
Priority LOW 34CWE-639Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 1 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-639.
Summary
Traefik is an HTTP reverse proxy and load balancer. Versions prior to 2.11.6, 3.0.4, and 3.1.0-rc3 have a vulnerability that allows bypassing IP allow-lists via HTTP/3 early data requests in QUIC 0-RTT handshakes sent with spoofed IP addresses. Versions 2.11.6, 3.0.4, and 3.1.0-rc3 contain a patch for this issue. No known workarounds are available.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00594 48th percentileScored 2026-11-07
Fix Partial traefik (traefik): 2.11.6, 3.0.4, 3.1.0-rc3github.com/traefik/traefik/v2 (Go): 2.11.6+1 more productRed Hat: 1 advisoryRed Hat: 1 fixed, 2 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| traefik | traefik | before 2.11.6; 3.0.0-beta3 to before 3.0.4; 3.1.0-rc1 to before 3.1.0-rc3 | 2.11.6, 3.0.4, 3.1.0-rc3 | Patch available | CNA |
| — | github.com/traefik/traefik/v2 (Go) | before 2.11.6 | 2.11.6 | Patch available | GHSA-gxrv-wf35-62w9 |
| — | github.com/traefik/traefik/v3 (Go) | 3.0.0-beta3 to before 3.0.4 | 3.0.4 | Patch available | GHSA-gxrv-wf35-62w9 |
| — | github.com/traefik/traefik/v3 (Go) | 3.1.0-rc1 to before 3.1.0-rc3 | 3.1.0-rc3 | Patch available | GHSA-gxrv-wf35-62w9 |
- traefik Vendortraefik Affected before 2.11.6; 3.0.0-beta3 to before 3.0.4; 3.1.0-rc1 to before 3.1.0-rc3 Fixed in 2.11.6, 3.0.4, 3.1.0-rc3 Patch available CNA
- github.com/traefik/traefik/v2 (Go) Vendor— Affected before 2.11.6 Fixed in 2.11.6 Patch available GHSA-gxrv-wf35-62w9
- github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.0.0-beta3 to before 3.0.4 Fixed in 3.0.4 Patch available GHSA-gxrv-wf35-62w9
- github.com/traefik/traefik/v3 (Go) Vendor— Affected 3.1.0-rc1 to before 3.1.0-rc3 Fixed in 3.1.0-rc3 Patch available GHSA-gxrv-wf35-62w9
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* | before 2.11.6; 3.0.0 to before 3.0.4 | Vulnerable | traefik |
| cpe:2.3:a:traefik:traefik:3.1.0:-:*:*:*:*:*:* | 3.1.0 | Vulnerable | traefik |
| cpe:2.3:a:traefik:traefik:3.1.0:rc1:*:*:*:*:*:* | 3.1.0 rc1 | Vulnerable | traefik |
| cpe:2.3:a:traefik:traefik:3.1.0:rc2:*:*:*:*:*:* | 3.1.0 rc2 | Vulnerable | traefik |
- cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* Versions before 2.11.6; 3.0.0 to before 3.0.4 Vulnerable ·traefik
- cpe:2.3:a:traefik:traefik:3.1.0:-:*:*:*:*:*:* Versions 3.1.0 Vulnerable ·traefik
- cpe:2.3:a:traefik:traefik:3.1.0:rc1:*:*:*:*:*:* Versions 3.1.0 rc1 Vulnerable ·traefik
- cpe:2.3:a:traefik:traefik:3.1.0:rc2:*:*:*:*:*:* Versions 3.1.0 rc2 Vulnerable ·traefik
Remediation
- Fix · CNA traefik (traefik) Fixed in 2.11.6, 3.0.4, 3.1.0-rc3
- Fix · GHSA-gxrv-wf35-62w9 github.com/traefik/traefik/v2 (Go) Fixed in 2.11.6 Advisory →
- Fix · GHSA-gxrv-wf35-62w9 github.com/traefik/traefik/v3 (Go) Fixed in 3.0.4 Advisory →
- Fix · GHSA-gxrv-wf35-62w9 github.com/traefik/traefik/v3 (Go) Fixed in 3.1.0-rc3 Advisory →
Red Hat 1 advisory
- RHSA-2025:15847 Released 2025-09-15 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.23.0 Release.
- Red Hat OpenShift Dev Spaces (RHOSDS) 3.23 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/dashboard-rhel9, registry.redhat.io/devspaces/machineexec-rhel9 +3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Dev Spaces | Affected | No fix yet |
| Red Hat OpenShift GitOps | Affected | No fix yet |
| Red Hat OpenShift Dev Spaces (RHOSDS) 3.23 | Fixed | RHSA-2025:15847 |
Not affected: 1 product
- Red Hat OpenShift Dev Spaces (RHOSDS) 3.23
Timeline
- 2026-10-02 Threatist record created from CVE-2024-39321
- 2026-10-03 Alias added: GHSA-gxrv-wf35-62w9
References
More Traefik vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2023-25774 Uncontrolled Resource Consumption in Traefik CVSS 3.1HIGH 7.5
- TI-2025-40914 Traefik doesn't Prevent Path Normalization Bypass in Router + Middleware Rules CVSS 4.0MEDIUM 6.9
- TI-2022-07529 Authorization header displayed in the debug logs CVSS 3.1MEDIUM 6.5
- TI-2024-30459 HTTP client can remove the X-Forwarded headers in Traefik CVSS 3.1CRITICAL 9.8
- TI-2026-60261 Traefik v3.7.0 Authentication Bypass via from-to-www-redirect CVSS 4.0CRITICAL 9.3
Sources
- CVE-2024-39321 · CVE Program
- CVE-2024-39321 · NVD
- FIRST EPSS
- GHSA-gxrv-wf35-62w9 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-39321 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences