Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-295.
Summary
Emissary-Ingress (formerly Ambassador API Gateway) through 1.13.9 allows attackers to bypass client certificate requirements (i.e., mTLS cert_required) on backend upstreams when more than one TLSContext is defined and at least one configuration exists that does not require client certificate authentication. The attacker must send an SNI specifying an unprotected backend and an HTTP Host header specifying a protected backend. (2.x versions are unaffected. 1.x versions are unaffected with certain configuration settings involving prune_unreachable_routes and a wildcard Host resource.)
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:getambassador:emissary-ingress:*:*:*:*:*:*:*:* | up to 1.13.9 | Vulnerable | Getambassador |
- cpe:2.3:a:getambassador:emissary-ingress:*:*:*:*:*:*:*:* Versions up to 1.13.9 Vulnerable ·Getambassador
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-36371
- 2026-10-03 Alias added: GHSA-hc2q-w3c3-348m
References
Sources
- CVE-2021-36371 · CVE Program
- CVE-2021-36371 · NVD
- FIRST EPSS
- GHSA-hc2q-w3c3-348m · GitHub Advisory Database · CC BY 4.0
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