XS::Parse::Infix versions from 0.40 through 0.49 for Perl treat a number as an array reference
Summary
| CVE | CVE-2026-85644 |
|---|---|
| State | PUBLISHED |
| Assigner | CPANSec |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-28 17:17:51 UTC |
| Updated | 2026-09-30 20:17:34 UTC |
| Description | XS::Parse::Infix versions from 0.40 through 0.49 for Perl treat a number as an array reference. The wrapper function XS::Parse::Infix generates for a list-associative infix operator checks whether arguments are array references, but it tests using SvRV() rather than SvROK(). SvRV() reads a union slot that only holds a referent once SvROK(sv) is true, so the guard never validates that it is a reference. For an IV or NV that slot holds the number itself, SvRV() returns the caller's value and SvTYPE() dereferences it at offset 12. This will generally result in a segmentation fault. An application that hands the wrapper a list built from decoded input (for example, from JSON) lets whoever supplies a number in that list choose the address that the interpreter dereferences. An ordinary string's byte 12 is rarely SVt_PVAV so the guard croaks by luck, but an attacker-crafted string carrying 0x0b there passes, and the buffer is then used as an AV head, with AvARRAY taken from bytes 16-23 and its entries pushed onto the Perl stack as live SVs. A simple proof-of-concept uses the zip operator: use Syntax::Operator::Zip 'zip'; my @args = ([1], 2); zip(@args); |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.001850000 probability, percentile 0.072550000 (date 2026-09-29)
Problem Types: CWE-125 | CWE-843 | CWE-843 CWE-843 Access of Resource Using Incompatible Type ('Type Confusion') | CWE-125 CWE-125 Out-of-bounds Read
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
There are no known software configurations currently associated with this CVE in NVD or the CVE Program record.
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.openwall.com/lists/oss-security/2026/09/28/14 | af854a3a-2127-422b-91ae-364da2661108 | www.openwall.com | |
| metacpan.org/release/PEVANS/XS-Parse-Keyword-0.50/diff/PEVANS/XS-Parse-Key... | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| metacpan.org/release/PEVANS/XS-Parse-Keyword-0.50/changes | 9b29abf9-4ab0-4765-b253-1875cd9b441e | metacpan.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
Solutions
CNA: Upgrade to XS-Parse-Keyword 0.50 or later.
Workarounds
CNA: For deployments that cannot upgrade, ensure that correct arguments (only array references where they are expected) are passed to list-associative operators that are defined with XS::Parse::Infix, such as those in Syntax::Operator::Zip.
There are currently no legacy QID mappings associated with this CVE.