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

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.

Published: 2026-05-13 Last update: 2026-05-13 Assigner: 9b29abf9-4ab0-4765-b253-1875cd9b441e Source: 9b29abf9-4ab0-4765-b253-1875cd9b441e
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-8463 is rated Low Risk (30/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.33%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-8463

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.33% +0.30%
2 2026-05-14 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-8463

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-8463

GitHub Security Advisory for CVE-2026-8463

GHSA-3p6c-7qjr-35x9 · Severity: medium — Crypt::Argon2 versions from 0.017 before 0.031 for Perl perform a heap out-of-bounds read in...

OS Trackers for CVE-2026-8463

vendor priority summary link
debian not yet assigned CVE-2026-8463 not yet assigned priority: Debian including 1 source packages (libcrypt-argon2-perl), 4 status rows across 4 suites (bookworm, forky, sid, trixie): open 2, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-8463
ubuntu medium CVE-2026-8463 medium priority: Ubuntu including 1 source packages (libcrypt-argon2-perl), 5 status rows across 5 suites (jammy, noble, questing, resolute, upstream): needs-triage 3, DNE 1, released 1. https://ubuntu.com/security/CVE-2026-8463

Affected software / configurations for CVE-2026-8463

Vendor Product Version Raw CPE
leont crypt::argon2 >= 0.017, < 0.031 cpe:2.3:a:leont:crypt\:\:argon2:*:*:*:*:*:perl:*:*

References for CVE-2026-8463

cvelogic Threat Intelligence