CVE-2026-42327
HighSummary
In the rust-openssl library, versions from 0.9.7 to before 0.10.79, there is a vulnerability related to improper processing of OCSP responder URLs from a certificate's AIA extension. The use of invalid bytes in the OCSP accessLocation can lead to a violation of the UTF-8 invariant, resulting in undefined behavior.
Risk Assessment
Organizations may be exposed to unpredictable application behavior, which could lead to crashes or exploitation of the vulnerability by attackers. In particular, this may impact the security of applications using this library.
Recommendation
It is recommended to update the rust-openssl library to version 0.10.79 or later to mitigate this vulnerability. A code audit should also be conducted to identify potential areas where similar behavior may occur.
Other vulnerabilities in rust-openssl
See all- CVE-2026-45784High
Vulnerability in rust-openssl from 0.10.50 to 0.10.80. The `CipherCtxRef::cipher_update_inplace` function incorrectly sizes output buffers for AES key-wrap-with-padding ciphers (`EVP_aes_{128,192,256}_wrap_pad`), causing up to 7 bytes of out-of-bounds write and heap corruption when input length is not a multiple of 8.
- CVE-2026-41898Medium
A vulnerability in the rust-openssl library (versions 0.9.24 through 0.10.78) causes the PSK and cookie callbacks to not validate the user closure's return value against the buffer size. This can lead to buffer overflows and other unintended consequences.
- CVE-2026-41681High
In the rust-openssl library versions 0.10.39 through 0.10.77, there is a buffer overflow vulnerability in the EVP_DigestFinal() function. This function always writes EVP_MD_CTX_size(ctx) bytes to the output buffer, which when the buffer is smaller leads to a write past its end and potential stack corruption. The issue is reachable from safe Rust code.
- CVE-2026-41678High
In the rust-openssl library before version 0.10.78, the aes::unwrap_key() function contains an incorrect assertion: it checks out.len() + 8 <= in_.len() instead of the correct out.len() >= in_.len() - 8. This leads to an out-of-bounds write when a smaller output buffer is provided.
- CVE-2026-41676High
In rust-openssl versions 0.9.27 through 0.10.77, a heap/stack overflow vulnerability exists in Deriver::derive and PkeyCtxRef::derive functions. On OpenSSL 1.1.x, EVP_PKEY_derive ignores the provided buffer size and writes the full shared secret, causing overflow even from safe Rust code.
Original NVD description (English source)
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.