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.
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History

Fri, 18 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Description 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.
Title rustls webpki Name Constraints URI Validation Bypass
Weaknesses CWE-295
References
Metrics cvssV3_1

{'score': 2.2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 2.1, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-18T13:20:10.899Z

Reserved: 2026-09-18T11:00:32.756Z

Link: CVE-2026-93600

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-18T14:19:11.563

Modified: 2026-09-18T14:19:11.563

Link: CVE-2026-93600

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses