Answer in brief
CVE-2019-9901 records a Critical severity (CVSS 10.0) vulnerability in EnvoyProxy Envoy Missing HTTP URL path normalization. The current sources do not mark it as known exploited. The current feed maps github.com/envoyproxy/envoy (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 10.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps github.com/envoyproxy/envoy (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| github.com/envoyproxy/envoygo | >=0 <1.9.1 | 1.9.1 |
Published upstream
May 24, 2022
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Aug 7, 2026
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.
Quoted source text, attributed separately from HOL analysis.