CVE-2026-109391Published

Square Squash through commit e73f280 Unauthenticated YAML Deserialization via Symbolication API

Exact source revision recorded 27 Oct 2026 03:22:55 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-109391

Published

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.

Source published: 12 Oct 2026 15:16:39 UTC
Source modified: 27 Oct 2026 01:30:40 UTC
Observed here: 27 Oct 2026 03:22:55 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 9.2 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

CVSS 3.1 · 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H