UBUNTU-CVE-2026-85644

See a problem?
Please try reporting it to the source first.
Source
https://ubuntu.com/security/CVE-2026-85644
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85644.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-85644
Upstream
  • CVE-2026-85644
Downstream
Related
Published
2026-09-28T17:17:00Z
Modified
2026-10-21T04:30:02Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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);

References

Affected packages

Ubuntu:26.10 / libxs-parse-keyword-perl

Package

Name
libxs-parse-keyword-perl
Purl
pkg:deb/ubuntu/libxs-parse-keyword-perl?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.49-1ubuntu1

Affected versions

0.*
0.49-1
0.49-1build1

Ecosystem specific 

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "libxs-parse-keyword-perl",
            "binary_version":  "0.49-1ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85644.json"

Ubuntu:26.04:LTS / libxs-parse-keyword-perl

Package

Name
libxs-parse-keyword-perl
Purl
pkg:deb/ubuntu/libxs-parse-keyword-perl?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.49-1ubuntu0.1

Affected versions

0.*
0.48-2
0.49-1

Ecosystem specific 

{
    "availability":  "No subscription required",
    "binaries":  [
        {
            "binary_name":  "libxs-parse-keyword-perl",
            "binary_version":  "0.49-1ubuntu0.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-85644.json"