CVE-2026-85644 XS::Parse::Infix versions from 0.40 through 0.49 for Perl treat a number as an array reference
Attacker-controlled numeric input in Perl infix operations triggers memory corruption, potentially allowing code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-85644?
CVE-2026-85644 is a high-severity memory corruption vulnerability in perl-XS-Parse-Keyword, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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);
Which versions are affected by CVE-2026-85644?
Linux distribution packages (4)
perl-XS-Parse-Keyword SUSE:Linux Enterprise Server 16.0 | All versions | 0.480.0-160000.3.1 |
perl-XS-Parse-Keyword SUSE:Linux Enterprise Server for SAP applications 16.0 | All versions | 0.480.0-160000.3.1 |
perl-XS-Parse-Keyword openSUSE:Leap 16.0 | All versions | 0.480.0-160000.3.1 |
perl-XS-Parse-Keyword openSUSE:Tumbleweed | All versions | 0.500.0-1.1 |
How do I fix CVE-2026-85644?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-85644 being exploited?
There is no known exploitation of CVE-2026-85644 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-85644, GHSA-ch9g-92vf-wwhv, MGASA-2026-0513, SUSE-SU-2026:24244-1, UBUNTU-CVE-2026-85644, USN-8940-1 and 2 more.