rust-openssl up to 0.10.77 derive out-of-bounds write

Summaryinfo

A vulnerability classified as critical has been found in rust-openssl up to 0.10.77. Affected by this vulnerability is the function Deriver::derive/PkeyCtxRef::derive. This manipulation causes out-of-bounds write. This vulnerability is handled as CVE-2026-41676. The attack can be initiated remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in rust-openssl up to 0.10.77 and classified as critical. Affected by this vulnerability is the function Deriver::derive/PkeyCtxRef::derive. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

rust-openssl provides OpenSSL bindings for the Rust programming language. From 0.9.27 to before 0.10.78, Deriver::derive (and PkeyCtxRef::derive) sets len = buf.len() and passes it as the in/out length to EVP_PKEY_derive, relying on OpenSSL to honor it. On OpenSSL 1.1.x, X25519, X448, DH and HKDF-extract ignore the incoming *keylen, unconditionally writing the full shared secret (32/56/prime-size bytes). A caller passing a short slice gets a heap/stack overflow from safe code. OpenSSL 3.x providers do check, so this only impacts older OpenSSL. This vulnerability is fixed in 0.10.78.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-41676 since 04/22/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/17/2026).

The vulnerability scanner Nessus provides a plugin with the ID 311730 (Fedora 43 : rust-openssl / rust-openssl-sys (2026-16a3cea414)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.10.78 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (311730) and CERT Bund (WID-SEC-2026-1657). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Oracle Linux

Productinfo

Type

• Network Encryption Software

Name

• rust-openssl

Version

• 0.10.0
• 0.10.1
• 0.10.2
• 0.10.3
• 0.10.4
• 0.10.5
• 0.10.6
• 0.10.7
• 0.10.8
• 0.10.9
• 0.10.10
• 0.10.11
• 0.10.12
• 0.10.13
• 0.10.14
• 0.10.15
• 0.10.16
• 0.10.17
• 0.10.18
• 0.10.19
• 0.10.20
• 0.10.21
• 0.10.22
• 0.10.23
• 0.10.24
• 0.10.25
• 0.10.26
• 0.10.27
• 0.10.28
• 0.10.29
• 0.10.30
• 0.10.31
• 0.10.32
• 0.10.33
• 0.10.34
• 0.10.35
• 0.10.36
• 0.10.37
• 0.10.38
• 0.10.39
• 0.10.40
• 0.10.41
• 0.10.42
• 0.10.43
• 0.10.44
• 0.10.45
• 0.10.46
• 0.10.47
• 0.10.48
• 0.10.49
• 0.10.50
• 0.10.51
• 0.10.52
• 0.10.53
• 0.10.54
• 0.10.55
• 0.10.56
• 0.10.57
• 0.10.58
• 0.10.59
• 0.10.60
• 0.10.61
• 0.10.62
• 0.10.63
• 0.10.64
• 0.10.65
• 0.10.66
• 0.10.67
• 0.10.68
• 0.10.69
• 0.10.70
• 0.10.71
• 0.10.72
• 0.10.73
• 0.10.74
• 0.10.75
• 0.10.76
• 0.10.77

Support

• end of life (old version)

Website

• Product: https://github.com/rust-openssl/rust-openssl/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion