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.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-502"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109391.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"last_affected": "e73f2805f9eb30780a5c213b001f0f4255660fbf"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}