---
id: CVE-2026-93600
title: >-
  rustls-webpki (rustls/webpki) versions 0.101.0 through 0.103.11 and
  0.104.0-alpha releases before 0.104.0-alpha.6 ignore X.509 name constraints
  that apply to URI names, causing such constraints to be accepted rather than
  enforced
summary: >-
  rustls-webpki (rustls/webpki) versions 0.101.0 through 0.103.11 and
  0.104.0-alpha releases before 0.104.0-alpha.6 ignore X.509 name constraints
  that apply to URI names, causing such constraints to be accepted rather than
  enforced. Becaus…
severity: low
cvss: 2.2
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-295
vendor: rustls
product: webpki
affected:
  - webpki >= 0.101.0 < 0.103.12
  - webpki >= 0.104.0-alpha.1 < 0.104.0-alpha.6
patched:
  - rustls-webpki 0.104.0-alpha.6
published: '2026-09-18'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:25:55.870'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93600'
references:
  - url: 'https://github.com/rustls/webpki/security/advisories/GHSA-965h-392x-2mh5'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/rustls-webpki-name-constraints-uri-validation-bypass
    label: disclosure@vulncheck.com
  - url: 'https://crates.io/crates/rustls-webpki'
  - url: 'https://rustsec.org/advisories/RUSTSEC-2026-0098.html'
  - url: 'https://github.com/rustls/webpki'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93600.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93600'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2538296'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93600'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93600'
tags:
  - nvd
  - cve.org
  - osv
  - rust
  - csaf
  - vex
  - red-hat
epss: 0.00177
epssPercentile: 0.06502
aliases:
  - RUSTSEC-2026-0098
  - GHSA-965h-392x-2mh5
ecosystem: rust
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-21T16:22:50.273345Z'
ingestedAt: '2026-09-18T13:41:41.662Z'
---

## Overview

rustls-webpki (rustls/webpki) versions 0.101.0 through 0.103.11 and 0.104.0-alpha releases before 0.104.0-alpha.6 ignore X.509 name constraints that apply to URI names, causing such constraints to be accepted rather than enforced. Because name constraints are restrictions on otherwise properly issued certificates, the flaw is only reachable after successful signature verification and requires a misissued certificate to exploit; the library also provides no API for asserting URI names, and URI name constraints are otherwise unimplemented. Versions 0.103.12 and 0.104.0-alpha.6 reject URI name constraints unconditionally.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-93600)

Affected packages:

- `rustls-webpki >= 0.104.0-alpha.1, < 0.104.0-alpha.6`

Patched in:

- `rustls-webpki 0.104.0-alpha.6`

Source: https://osv.dev/vulnerability/RUSTSEC-2026-0098

## Vendor advisories

- **Red Hat VEX** · Low · affected: Confidential Cluster Operator, Confidential Compute Attestation, Logging Subsystem for Red Hat OpenShift, Migration Toolkit for Applications 8, OpenShift Lightspeed, OpenShift Service Mesh 3, … · no fix planned: Logging Subsystem for Red Hat OpenShift, Migration Toolkit for Applications 8, OpenShift Service Mesh 3, Red Hat Ansible Automation Platform 2, … · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93600.json)