CVE-2026-2588 in Crypt::NaCl::Sodium
Summary
by MITRE • 02/23/2026
Crypt::NaCl::Sodium versions through 2.001 for Perl has an integer overflow flaw on 32-bit systems.
Sodium.xs casts a STRLEN (size_t) to unsigned long long when passing a length pointer to libsodium functions. On 32-bit systems size_t is typically 32-bits while an unsigned long long is at least 64-bits.
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Analysis
by VulDB Data Team • 03/04/2026
The vulnerability described in CVE-2026-2588 represents a critical integer overflow flaw affecting Crypt::NaCl::Sodium Perl module versions through 2.001. This issue specifically manifests on 32-bit systems where the underlying data type characteristics create a dangerous mismatch in memory handling. The flaw stems from the Sodium.xs implementation which performs a type casting operation that transforms a STRLEN type into an unsigned long long when communicating with libsodium functions. STRLEN is defined as size_t in Perl's context, which on 32-bit architectures typically resolves to a 32-bit unsigned integer, while the target parameter expects an unsigned long long that is guaranteed to be at least 64 bits according to C standard requirements.
The technical implementation of this vulnerability creates a scenario where input values that exceed the 32-bit integer range can cause unexpected behavior when the casting operation occurs. When a length parameter exceeds the maximum value representable by a 32-bit unsigned integer, the conversion to 64-bit unsigned long long can result in loss of precision or unexpected wrapping behavior that may lead to memory corruption or buffer overflows. This type of integer overflow vulnerability falls under CWE-190, which specifically addresses integer overflow and underflow conditions, and more precisely maps to CWE-191, which deals with integer underflow. The flaw represents a classic example of how type casting between different sized integer types can create security vulnerabilities when the source type has insufficient bit width to represent the full range of values that might be encountered.
The operational impact of this vulnerability on 32-bit systems is significant as it could potentially allow attackers to manipulate the length parameters passed to libsodium functions in ways that bypass normal input validation checks. This creates opportunities for memory corruption that might be exploitable to achieve arbitrary code execution or denial of service conditions. The vulnerability is particularly concerning because it affects cryptographic operations that are fundamental to secure communications, potentially compromising the integrity of encrypted data or authentication mechanisms. Systems running 32-bit Perl environments with the affected Crypt::NaCl::Sodium module are at risk, especially in environments where untrusted input is processed through cryptographic functions.
Mitigation strategies for this vulnerability should prioritize immediate patching of the Crypt::NaCl::Sodium module to version 2.002 or later, which addresses the integer overflow by implementing proper bounds checking and ensuring appropriate type handling for 32-bit systems. Organizations should also consider implementing additional input validation measures that explicitly check length parameters against expected maximum values before they are passed to the cryptographic functions. System administrators should monitor for any instances of 32-bit Perl installations running this module and ensure they are updated promptly. From an operational security perspective, this vulnerability aligns with ATT&CK technique T1059.007 for executing malicious code through Perl scripts, and could be leveraged as part of broader exploitation chains targeting cryptographic implementations. The vulnerability demonstrates the importance of careful type handling in systems that interface with cryptographic libraries, where even seemingly minor casting operations can have severe security implications.