PT-2026-40603 · Leont · Crypt::Argon2

Published 2026-05-13 · Updated 2026-05-13 · CVE-2026-8463

NVD

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Crypt::Argon2 versions from 0.017 before 0.031 for Perl perform a heap out-of-bounds read in argon2 verify on empty encoded input.

The auto-detect form of argon2 verify passes encoded len - 1 as the length argument to memchr without checking that encoded len is non-zero. When the encoded string is empty, the size t subtraction underflows to SIZE MAX and memchr scans adjacent heap memory looking for a '$' separator byte.

A caller that invokes argon2 verify against a stored hash that may legitimately be empty (for example a placeholder row or a NULL column materialised as an empty string) reads out-of-bounds heap memory, which can crash the process or leak the position of an adjacent '$' byte into subsequent parsing.

Fix

Integer Underflow

Buffer Over-read

Weakness Enumeration

CWE-191

CWE-126

Related Identifiers

CVE-2026-8463

Affected Products

Crypt::Argon2

References · 4

• https://github.com/Leont/crypt-argon2/commit/92eac03ce63d541e0ead7ea5a89b9b67ce0c0e64.patch · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-8463 · Security Note
• http://openwall.com/lists/oss-security/2026/05/13/4 · Note
• https://metacpan.org/release/LEONT/Crypt-Argon2-0.031/changes · Note