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
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.
INFO
Published Date :
May 13, 2026, 2:18 p.m.
Last Modified :
May 13, 2026, 7:23 p.m.
Remotely Exploit :
Yes !
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Crypt::Argon2 to a version that fixes the memchr length issue.
- Ensure encoded input length is validated before calling argon2_verify.
- Avoid passing empty encoded input to argon2_verify.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-8463.
| URL | Resource |
|---|---|
| https://github.com/Leont/crypt-argon2/commit/92eac03ce63d541e0ead7ea5a89b9b67ce0c0e64.patch | Patch |
| https://metacpan.org/release/LEONT/Crypt-Argon2-0.031/changes | Release Notes |
| http://www.openwall.com/lists/oss-security/2026/05/13/4 | Mailing List Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-8463 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-8463
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-8463 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-8463 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Added CPE Configuration OR *cpe:2.3:a:leont:crypt::argon2:*:*:*:*:*:perl:*:* versions from (including) 0.017 up to (excluding) 0.031 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/05/13/4 Types: Mailing List, Third Party Advisory Added Reference Type CPANSec: https://github.com/Leont/crypt-argon2/commit/92eac03ce63d541e0ead7ea5a89b9b67ce0c0e64.patch Types: Patch Added Reference Type CPANSec: https://metacpan.org/release/LEONT/Crypt-Argon2-0.031/changes Types: Release Notes -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
May. 13, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/05/13/4 -
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
May. 13, 2026
Action Type Old Value New Value 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. Added CWE CWE-191 Added CWE CWE-126 Added Reference https://github.com/Leont/crypt-argon2/commit/92eac03ce63d541e0ead7ea5a89b9b67ce0c0e64.patch Added Reference https://metacpan.org/release/LEONT/Crypt-Argon2-0.031/changes