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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| LEONT | Crypt::Argon2 | unaffected |
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Solution
Upgrade to Crypt-Argon2 0.031 or later.
Workaround
No workaround given by the vendor.
Wed, 13 May 2026 13:15:00 +0000
| 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 |
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| References |
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Projects
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MITRE
Status: PUBLISHED
Assigner: CPANSec
Published:
Updated: 2026-05-13T12:40:35.917Z
Reserved: 2026-05-13T11:08:17.272Z
Link: CVE-2026-8463
Vulnrichment
No data.
NVD
Status : Undergoing Analysis
Published: 2026-05-13T14:18:17.140
Modified: 2026-05-13T15:57:03.607
Link: CVE-2026-8463
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-05-13T16:00:17Z