CVE-2026-42327
highpriority · track · 0EPSS 0.002 · 11 %ileEURUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
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affected products (8)
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advisories (1)
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- GHSA-xp3w-r5p5-63rrrust-openssl has undefined behavior in X509Ref::ocsp_responders for certificates with non-UTF-8 OCSP URLs2026-05-05ghsa · osvUS
`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.
also known as (5)
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sources
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references (4)
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