CVE-2026-109391

Square Squash through commit e73f280 Unauthenticated YAML Deserialization via Symbolication API

Published Oct 12, 2026 CVSS 4.0 · 9.2 Critical EPSS < 1% KEV · Not listed
Description
Square Squash through commit e73f280 contains an insecure deserialization vulnerability that allows unauthenticated attackers to store crafted YAML via the POST /api/1.0/symbolication endpoint. When occurrences referencing the attacker-controlled symbolication UUID are symbolicated, the stored values are passed to YAML.load with SafeYAML in unsafe mode, enabling arbitrary Ruby object deserialization and potential code execution.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Squash
Squash square Squash
CPEs cpe:2.3:a:squash:square_squash:-:*:*:*:*:*:*:*
Vendors & Products Squash
Squash square Squash
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Square
Square squash
Vendors & Products Square
Square squash
Type Values Removed Values Added
Description Square Squash through commit e73f280 contains an insecure deserialization vulnerability that allows unauthenticated attackers to store crafted YAML via the POST /api/1.0/symbolication endpoint. When occurrences referencing the attacker-controlled symbolication UUID are symbolicated, the stored values are passed to YAML.load with SafeYAML in unsafe mode, enabling arbitrary Ruby object deserialization and potential code execution.
Title Square Squash through commit e73f280 Unauthenticated YAML Deserialization via Symbolication API
Weaknesses CWE-502
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.2, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 27, 2026, 1:30 AM
Reserved
Oct 12, 2026, 2:40 PM
Status
Deferred
Published
Oct 12, 2026, 4:17 PM
Modified
Oct 16, 2026, 6:25 PM