CVE-2026-42327 Details
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.
A vulnerability in rust-openssl versions 0.9.7 prior to 0.10.79 allows for undefined behavior when handling OCSP responder URLs from a certificate's AIA extension. The issue arises because the X509Ref::ocsp_responders method returns these URLs as OpensslString, which improperly assumes the raw bytes are valid UTF-8. OpenSSL does not guarantee that the underlying IA5String is ASCII, leading to the possibility of non-UTF-8 bytes causing safe Rust code to create a &str that violates the UTF-8 invariant.
Users can upgrade to rust-openssl version 0.10.79 or later to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed May 14, 2026CISA-ADP
Assessed May 15, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/rust-openssl/rust-openssl/security/advisories/GHSA-xp3w-r5p5-63rr | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-20 | Improper Input Validation | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| rust-openssl | >= 0.9.7 (semver) |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 14, 2026 | New CVE Received | [email protected] |