Envoy 1.9.0 and before does not normalize HTTP URL paths.
Priority MEDIUM 51CWE-706Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA, GitHub and Red Hat.
Summary
Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.
Why it matters now
EPSS 0.04951 92nd percentileScored 2026-11-07
Fix Fixed github.com/envoyproxy/envoy (Go): 1.9.1Red Hat: 1 advisory
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 |
| — | github.com/envoyproxy/envoy (Go) | before 1.9.1 | 1.9.1 | Patch available | GHSA-2wmf-p7f8-w42h |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- github.com/envoyproxy/envoy (Go) Vendor— Affected before 1.9.1 Fixed in 1.9.1 Patch available GHSA-2wmf-p7f8-w42h
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* | up to 1.9.0 | Vulnerable | envoyproxy |
- cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* Versions up to 1.9.0 Vulnerable ·envoyproxy
Remediation
- Fix · GHSA-2wmf-p7f8-w42h github.com/envoyproxy/envoy (Go) Fixed in 1.9.1 Advisory →
Red Hat 1 advisory
- RHSA-2019:0741 Released 2019-04-10 · Red Hat rating ImportantIstio-Proxy Security Update
- Red Hat OpenShift Service Mesh 0 Tech Preview servicemesh-proxy-0.9.1-1.el7
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Service Mesh 0 Tech Preview | Fixed | RHSA-2019:0741 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-9901
- 2026-10-03 Alias added: GHSA-2wmf-p7f8-w42h
References
Advisory 3
Other 6
- https://groups.google.com/forum/#%21topic/envoy-announce/VoHfnDqZiAM
- https://github.com/envoyproxy/envoy/security/advisories/GHSA-xcx5-93pw-jw2w
- https://github.com/envoyproxy/envoy/commit/e668e669677e52a00d99652b5a260d1cedafdfa8
- https://github.com/envoyproxy/envoy
- https://github.com/envoyproxy/envoy/blob/main/security/postmortems/cve-2019-9900.md
- https://groups.google.com/forum/#!topic/envoy-announce/VoHfnDqZiAM
More envoyproxy Envoy vulnerabilities
- TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2024-20001 HTTP/2: CPU exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
- TI-2024-18524 HTTP/2: memory exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
- TI-2023-12215 Envoy client may fake the header `x-envoy-original-path` CVSS 3.1CRITICAL 9.1
- TI-2023-18002 Envoy vulnerable to OAuth2 credentials exploit with permanent validity CVSS 3.1CRITICAL 9.8
Sources
- CVE-2019-9901 · CVE Program
- CVE-2019-9901 · NVD
- FIRST EPSS
- GHSA-2wmf-p7f8-w42h · GitHub Advisory Database · CC BY 4.0
- CVE-2019-9901 · 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