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CVE Record

CVE-2026-32695: Traefik has Knative Ingress Rule Injection that Allows Host Restriction Bypass

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 3.6.11 and 3.7.0-ea.2, Traefik's Knative provider builds router rules by interpolating user-controlled values into backtick-delimited rule expressions without escaping. In live cluster validation, Knative `rules[].hosts[]` was exploitable for host restriction bypass (for example `tenant.example.com`) || Host(`attacker.com`), producing a router that serves attacker-controlled hosts. Knative `headers[].exact` also allows rule-syntax injection and proves unsafe rule construction. In multi-tenant clusters, this can route unauthorized traffic to victim services and lead to cross-tenant traffic exposure. Versions 3.6.11 and 3.7.0-ea.2 patch the issue.

HighCVSS 7.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

Traefik can mistakenly trust attacker-controlled Knative routing values. In affected versions, a tenant with permission to create or modify Knative ingress rules could make Traefik accept traffic for unauthorized hostnames, potentially exposing another tenant's service traffic. This is most urgent for multi-tenant Kubernetes/Knative environments.

Executive priority

Prioritize remediation for shared Kubernetes/Knative platforms because the impact is cross-tenant traffic exposure. Treat internet-facing or customer-hosting clusters as urgent. Non-Knative or isolated single-tenant deployments should validate applicability, then patch on the normal high-severity schedule.

Technical view

The Knative provider constructs router rule expressions by interpolating hosts and exact header values into backtick-delimited Traefik rules without escaping. This permits rule-syntax injection and host restriction bypass. The CVE affects Traefik before 3.6.11 and 3.7.0-ea.1 before 3.7.0-ea.2.

Likely exposure

Exposure is likely where Traefik uses the Knative provider and untrusted or semi-trusted tenants can control Knative ingress hosts or exact header values. Single-tenant deployments or deployments without the Knative provider are less directly exposed, but should still verify versions and configuration.

Exploitation context

The source bundle reports live cluster validation of host restriction bypass and unsafe header rule construction. It does not cite public active exploitation, and KEV is false. Exploitation requires low-privileged access to influence relevant Knative ingress configuration.

Researcher notes

The core issue is expression injection in Traefik rule construction, mapped to CWE-74 and CWE-917. Evidence supports confidentiality impact with changed scope, not integrity or availability impact. Public sources name fixed versions but do not provide broader exploit telemetry in the supplied bundle.

Mitigation direction

  • Upgrade Traefik to 3.6.11 or later in the 3.6 line.
  • Upgrade 3.7 early-access deployments to 3.7.0-ea.2 or later.
  • Check Red Hat advisory RHSA-2026:10175 for product-specific remediation.
  • Restrict who can create or modify Knative ingress and route objects.
  • Review vendor guidance before applying non-vendor workarounds.

Validation and detection

  • Inventory Traefik versions across clusters and images.
  • Confirm whether the Knative provider is enabled.
  • Review RBAC for users controlling Knative ingress hosts or headers.
  • Inspect recent Knative route changes for unusual host or exact-header values.
  • Verify upgraded instances report fixed Traefik versions.
Prepared
Confidence
high
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-74: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cwe · low confidence lookup

CWE-917: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-32695 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.7 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
8Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.7CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N3.14redhat-SADP
6.3CVSS 4.0MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N——GitHub_M

Vulnerability scoring details

Base CVSS 4.0 score

6.3Medium
CVSS 4.0 vector shape for CVE-2026-32695Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPgithub.com/traefik/traefik: Traefik: Cross-tenant traffic exposure and host restriction bypass via rule-syntax injection in Knative provider
other:Red Hat severity ratingcvssV3_1
  • 2026-03-27T14:01:07.317Z: Reported to Red Hat.
  • 2026-03-27T13:47:03.645Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
traefiktraefik< 3.6.11, >= 3.7.0-ea.1, < 3.7.0-ea.2Listed
Weakness

CWE details

CWE-74CWE-917

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.