Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-30909 is a critical-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Timlegge Crypt\. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 42th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-30909 is an integer overflow vulnerability (CWE-190) affecting Crypt::NaCl::Sodium versions through 2.002, a Perl module implementing the NaCl cryptography library. The issue resides in the bin2hex, encrypt, aes256gcm_encrypt_afternm, and seal functions, which fail to verify that the required output size remains below SIZE_MAX before allocation. This can trigger integer wraparound, resulting in an undersized output buffer. The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), reflecting severe potential impacts despite practical constraints.
Any remote, unauthenticated attacker able to supply inputs to affected functions could exploit this vulnerability. Exploitation requires extremely large input lengths—for bin2hex, binary length exceeding SIZE_MAX / 2; for encrypt and aes256gcm_encrypt_afternm, message length over SIZE_MAX - 16U; and for seal, encrypted length surpassing SIZE_MAX - 64U—making it unlikely in typical scenarios. Successful exploitation could lead to buffer underallocation, potentially causing memory corruption, application crashes, or incorrect cryptographic operations that compromise confidentiality, integrity, and availability.
Mitigation is available via a patch in pull request #24 at https://github.com/cpan-authors/crypt-nacl-sodium/pull/24.patch, which addresses the output size checks in the vulnerable functions. The referenced source code lines from the vulnerable version 2.002 (e.g., Sodium.xs at lines 2116, 2310, 3304, and 942 on metacpan.org) highlight the exact locations of the flaws for verification and patching. Security practitioners should update to a patched version beyond 2.002.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10199
Vulnerability Data
Crypt::NaCl::Sodium versions through 2.002 for Perl has potential integer overflows. bin2hex, encrypt, aes256gcm_encrypt_afternm and seal functions do not check that output size will be less than SIZE_MAX, which could lead to integer wraparound causing an undersized output buffer. Encountering this…
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issue is unlikely as the message length would need to be very large. For bin2hex() the bin_len would have to be > SIZE_MAX / 2 For encrypt() the msg_len would need to be > SIZE_MAX - 16U For aes256gcm_encrypt_afternm() the msg_len would need to be > SIZE_MAX - 16U For seal() the enc_len would need to be > SIZE_MAX - 64U
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect integer overflows before release.
Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.
Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.
Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.
Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.