CVE-2026-26310Public exploitNetwork attack vector

Service crash via scoped IPv6 address handling

Published Mar 10, 2026 · Updated Mar 10, 2026

Improper input validation in Envoy allows remote attackers to crash the proxy by supplying a scoped IPv6 address through DNS or original_src. Utility::getAddressWithPort converts the address to text and reconstructs it without preserving its IPv6 scope identifier, causing address creation to fail and the process to terminate. The DNS path requires a scoped address in a resolver response, while the original_src path requires that filter and a scoped IPv6 source; either condition interrupts proxied traffic.

CVSS severity5.9
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in Envoy allows remote attackers to crash the proxy by supplying a scoped IPv6 address through DNS or original_src. Utility::getAddressWithPort converts the address to text and reconstructs it without preserving its IPv6 scope identifier, causing address creation to fail and the process to terminate. The DNS path requires a scoped address in a resolver response, while the original_src path requires that filter and a scoped IPv6 source; either condition interrupts proxied traffic.

The record

CVE
CVE-2026-26310
Published
Mar 10, 2026
Updated
Mar 10, 2026
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.34.13
  2. Affected versionversion=>= 1.35.0, < 1.35.9
  3. Affected versionversion=>= 1.36.0, < 1.36.5
  4. Affected versionversion=>= 1.37.0, < 1.37.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Envoy Proxy · Envoyversion=< 1.34.13; version=>= 1.35.0, < 1.35.9; version=>= 1.36.0, < 1.36.5; version=>= 1.37.0, < 1.37.1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.9GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo