CVE-2026-8463

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

Published May 13, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

Upgrade to Crypt-Argon2 0.031 or later.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Leont crypt::argon2
Vendors & Products Leont crypt::argon2
Type Values Removed Values Added
First Time appeared Leont
Leont crypt\
CPEs cpe:2.3:a:leont:crypt\:\:argon2:*:*:*:*:*:perl:*:*
Vendors & Products Leont
Leont crypt\
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title 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
Weaknesses CWE-126
CWE-191
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
May 13, 2026, 5:19 PM
Reserved
May 13, 2026, 11:08 AM
Status
Analyzed
Published
May 13, 2026, 2:18 PM
Modified
Oct 26, 2026, 2:10 PM