rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.7 to before 0.10.79, X509Ref::ocsp_responders returns OCSP responder URLs from a certificate's AIA extension as OpensslString, whose Deref<Target = str> wraps the raw bytes with str::from_utf8_unchecked. OpenSSL does not enforce that the underlying IA5String is ASCII, so a certificate with non-UTF-8 bytes in its OCSP accessLocation causes safe Rust code to construct a &str that violates the UTF-8 invariant — resulting in undefined behavior. This vulnerability is fixed in 0.10.79.

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Source ID Title
Github GHSA Github GHSA GHSA-xp3w-r5p5-63rr rust-openssl has undefined behavior in X509Ref::ocsp_responders for certificates with non-UTF-8 OCSP URLs
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 20 May 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-475
References
Metrics threat_severity

None

cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

threat_severity

Important


Sun, 17 May 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Rust-openssl Project
Rust-openssl Project rust-openssl
Vendors & Products Rust-openssl Project
Rust-openssl Project rust-openssl

Fri, 15 May 2026 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 14 May 2026 20:45:00 +0000

Type Values Removed Values Added
Description rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.7 to before 0.10.79, X509Ref::ocsp_responders returns OCSP responder URLs from a certificate's AIA extension as OpensslString, whose Deref<Target = str> wraps the raw bytes with str::from_utf8_unchecked. OpenSSL does not enforce that the underlying IA5String is ASCII, so a certificate with non-UTF-8 bytes in its OCSP accessLocation causes safe Rust code to construct a &str that violates the UTF-8 invariant — resulting in undefined behavior. This vulnerability is fixed in 0.10.79.
Title rust-openssl: undefined behavior in X509Ref::ocsp_responders for certificates with non-UTF-8 OCSP URLs
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-15T18:05:15.921Z

Reserved: 2026-04-26T12:37:18.171Z

Link: CVE-2026-42327

cve-icon Vulnrichment

Updated: 2026-05-15T16:28:52.292Z

cve-icon NVD

Status : Deferred

Published: 2026-05-14T21:16:45.430

Modified: 2026-05-15T14:55:57.710

Link: CVE-2026-42327

cve-icon Redhat

Severity : Important

Publid Date: 2026-05-14T20:17:39Z

Links: CVE-2026-42327 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-20T02:00:11Z

Weaknesses