CVE-2026-41678: rust-openssl: Incorrect bounds assertion in aes key wrap
Summary aes::unwrapkey() has an incorrect bounds assertion on the out buffer size, which can lead to out-of-bounds write.
Details aes::unwrapkey() contains an incorrect assertion: it checks that out.len() + 8 <= in.len(), but this condition is reversed. The intended invariant is out.len() >= in.len() - 8, ensuring the output buffer is large enough.
Because of the inverted check, the function only accepts buffers at or below the minimum required size and rejects larger ones. If a smaller buffer is provided the function will write past the end of out by in.len() - 8 - out.len() bytes, causing an out-of-bounds write from a safe public function.
Impact Vulnerable applications using AES keywrap and allowing attacker controlled buffer sizes could have an attacker trigger an out-of-bounds write.
Other sources
rust-openssl provides OpenSSL bindings for the Rust programming language. From to before 0.10.78, aes::unwrapkey() contains an incorrect assertion: it checks that out.len() + 8 <= in.len(), but this condition is reversed. The intended invariant is out.len() >= in.len() - 8, ensuring the output buffer is large enough. Because of the inverted check, the function only accepts buffers at or below the minimum required size and rejects larger ones. If a smaller buffer is provided the function will write past the end of out by in.len() - 8 - out.len() bytes, causing an out-of-bounds write from a safe public function. This vulnerability is fixed in 0.10.78.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
rust/opensslto a version that resolves this vulnerability.Fixed in 0.10.78 - Upgrade
Upgrade
rust-opensslto a version that resolves this vulnerability.Fixed in 0.10.78
Event History
Frequently Asked Questions
What is the severity of CVE-2026-41678?
CVE-2026-41678 is classified as a high severity vulnerability due to the potential for out-of-bounds write.
How do I fix CVE-2026-41678?
To fix CVE-2026-41678, upgrade to version 0.10.79 or later of the rust-openssl package.
What is the impact of CVE-2026-41678?
The impact of CVE-2026-41678 can result in application crashes or potential exploitation by malicious actors due to out-of-bounds writes.
Which versions are affected by CVE-2026-41678?
CVE-2026-41678 affects versions of rust-openssl between 0.10.24 and 0.10.78 inclusive.
Who maintains the CVE-2026-41678 vulnerability information?
The CVE-2026-41678 vulnerability information is maintained by the Rust community, specifically related to the rust-openssl package.