CVE-2026-2588 identifies an integer overflow vulnerability in the Crypt::NaCl::Sodium Perl module, specifically versions through 2.001, when running on 32-bit systems. The root cause is the improper casting of the STRLEN type, which is a size_t (typically 32 bits on 32-bit systems), to an unsigned long long (at least 64 bits) when passing length pointers to underlying libsodium cryptographic functions. This mismatch can cause the length value to wrap around or overflow, leading to incorrect buffer size calculations. As a result, the cryptographic operations relying on these length parameters may process incorrect memory regions, potentially causing buffer overflows or memory corruption. Such memory corruption can undermine the confidentiality and integrity guarantees of cryptographic operations, possibly allowing attackers to manipulate encrypted data, leak sensitive information, or crash the application. The vulnerability is specific to 32-bit architectures because on 64-bit systems, size_t and unsigned long long are compatible in size, preventing the overflow. No patches or fixes are currently linked, and no known exploits have been reported in the wild. The flaw is categorized under CWE-190 (Integer Overflow or Wraparound). The vulnerability requires no user interaction but does require the use of the affected Perl module on a 32-bit system, which is less common in modern environments but still present in legacy or embedded systems. The vulnerability was published on February 22, 2026, and assigned by CPANSec. Because no CVSS score is provided, severity is assessed based on the potential impact on cryptographic security and the exploitation conditions.

The primary impact of CVE-2026-2588 is on the confidentiality and integrity of cryptographic operations performed by applications using the vulnerable Crypt::NaCl::Sodium Perl module on 32-bit systems. Exploitation could allow attackers to cause buffer overflows or memory corruption, potentially leading to unauthorized data disclosure, tampering with encrypted data, or denial of service through application crashes. This undermines the security guarantees of libsodium-based cryptography, which is widely trusted for secure communications and data protection. Organizations relying on legacy 32-bit systems or embedded devices running Perl with this module are at risk. The impact extends to any critical infrastructure, secure communications, or data protection systems that depend on this cryptographic library. Although no known exploits are currently reported, the vulnerability's presence in cryptographic code makes it a high-value target for attackers seeking to bypass encryption or cause service disruption. The scope is limited to 32-bit environments, reducing the overall affected population but still significant in sectors with legacy systems.

To mitigate CVE-2026-2588, organizations should: 1) Avoid using Crypt::NaCl::Sodium versions through 2.001 on 32-bit systems until a patched version is released. 2) Monitor for updates from the vendor or CPAN repository for a fixed release that correctly handles size_t to unsigned long long conversions. 3) Where possible, migrate applications and systems to 64-bit architectures to eliminate the casting issue. 4) Conduct code audits and testing on cryptographic modules to detect improper type conversions and integer overflows. 5) Employ memory safety tools such as AddressSanitizer during development and testing to catch potential buffer overflows. 6) Isolate or sandbox applications using this module to limit the impact of potential exploitation. 7) For critical systems, consider alternative cryptographic libraries that do not exhibit this vulnerability. 8) Implement runtime monitoring for abnormal crashes or memory corruption symptoms that could indicate exploitation attempts. These steps go beyond generic advice by focusing on architecture migration, code auditing, and runtime protections specific to this integer overflow flaw.