Answer in brief
CVE-2026-73549 records a Medium severity (CVSS 5.3) vulnerability in Envoy - Incomplete fix for CVE-2026-26310: copyInternetAddressAndPort crashes on scoped IPv6 addresses in ORIGINAL_DST clusters. The current sources do not mark it as known exploited. The current feed maps envoyproxy/envoy (generic). 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 5.3. 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 envoyproxy/envoy (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| envoyproxy/envoygeneric | <1.36.10 || >=1.37.0 <1.37.6 || >=1.38.0 <1.38.4 || >=1.39.0 <1.39.1 | 1.36.10, 1.37.6, 1.38.4, 1.39.1 |
Published upstream
Sep 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 21, 2026
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's Utility::copyInternetAddressAndPort and QUIC client-address paths reconstruct scoped IPv6 addresses through addressAsString and Ipv6Instance. The string includes a percent scope identifier that inet_pton cannot parse, causing an exception or abort. Kernel-provided scoped IPv6 destinations in ORIGINAL_DST transparent-proxy deployments, and affected QUIC connection paths, can therefore terminate the process. The relevant scope boundary is that the HTTP use_http_header override rejects scoped addresses earlier; the advisory's crash path requires a kernel-provided original destination or the affected QUIC path. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.
Quoted source text, attributed separately from HOL analysis.