Traefik before 3.7.7 Namespace Confusion via HTTPRoute ExtensionRef
Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.
- Published
- Jul 22, 2026
- Updated
- Aug 6, 2026
- EPSS
- 0.5% · 42th percentile
- CWE
- CWE-863
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 5.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| traefik | traefik | cpe:2.3:a:traefik:traefik |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- traefik traefik3.7.0 and later · before 3.7.7
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
traefik traefik
- 3.7.7not affected
- 3.7.0 and later · before 3.7.7affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Go | github.com/traefik/traefik | all versions | — |
| Go | Traefik | from 3.7.0 · before 3.7.7 | 3.7.7 |
Same product
traefik: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-88877Traefik v3.7.0 Authentication Bypass via from-to-www-redirect37Monitor
- CVE-2026-85595Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth37Monitor
- CVE-2026-88007Traefik HTTP/3 Backend NTLM Connection Reuse36Monitor
- CVE-2026-88009Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging35Monitor
- CVE-2025-32431Traefik has a possible vulnerability with the path matchers35Monitor
- CVE-2023-54365Traefik - Denial of Service via HTTP/2 Request Handling34Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| traefik traefik | 3.7.7 | Vendor (CNA) |
| Go:Traefik | 3.7.7 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- CuB3y0ndreporter
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-8559744 days apartTraefik before v2.11.55 and v3.0.0 through v3.7.10 mTLS Bypass via TLS Option Conflict32Monitor
- CVE-2026-656020 days apartTraefik before 3.6.23 IngressRouteTCP ServersTransport Namespace Bypass21Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0616 · Jul 23, 2026(Traefik Proxy Güvenlik Zafiyeti)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-863 · Incorrect AuthorizationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/traefik/traefik/commit/26c96a3935cafb473f4a5bae1886560d9aa4e4f0
- github.com/traefik/traefik/security/advisories/GHSA-qq9q-x9w4-chhj
- www.vulncheck.com/advisories/traefik-before-namespace-confusion-via-httproute-extensionref
Vendor advisories and official records. Exploit/PoC links are deliberately left out.