CVE-2019-9901
EnvoyProxy Envoy Missing HTTP URL path normalization
CVE-2019-9901 is a medium vulnerability (CVSS 6.5) in Envoyproxy Envoy, published April 25, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.95%, the 92nd percentile. Fixed in github.com/envoyproxy/envoy 1.9.1.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2019-9901- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AC:H/AV:N/A:L/C:L/I:L/PR:N/S:C/UI:N - Updated
- 2026-11-02
EUVDEUVD-2022-2065
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.
- Record
EUVD-2022-2065- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AC:H/AV:N/A:L/C:L/I:L/PR:N/S:C/UI:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-2wmf-p7f8-w42h
EnvoyProxy Envoy Missing HTTP URL path normalization
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.
- Record
GHSA-2wmf-p7f8-w42h- CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-706
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2019-9901- CVSS 3.0
- 6.5 Medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L - CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-706
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2019-9901- CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-2wmf-p7f8-w42h
EnvoyProxy Envoy Missing HTTP URL path normalization
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.
- Record
GHSA-2wmf-p7f8-w42h- CVSS 3.0
- 10.0 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-706
- Updated
- 2026-11-02
OSVRHSA-2019:0741
Red Hat Security Advisory: Istio-Proxy Security Update
- Record
RHSA-2019:0741- CVSS 3.0
- 8.3 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/envoyproxy/envoyGo |
through 1.9.0 | 1.9.1 |
github.com/envoyproxy/envoyGo |
before 1.9.1 | 1.9.1 |
servicemesh-proxyRed Hat:service_mesh:0 |
before 0:0.9.1-1.el7 | 0:0.9.1-1.el7 |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
envoyproxy.io/docs/envoy/v1.9.1/intro/version_history
github.com/envoyproxy/envoy/issues/6435
groups.google.com/forum
nvd.nist.gov/vuln/detail/CVE-2019-9901
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access.redhat.com/errata/RHSA-2019:0741
bugzilla.redhat.com/show_bug.cgi?id=1698020
security.access.redhat.com/data/csaf/v2/advisories/2019/rhsa-2019_0741.json
cve.org/CVERecord?id=CVE-2019-9900