CVE-2026-109391

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Source
https://cve.org/CVERecord?id=CVE-2026-109391
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-109391.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-109391
Published
2026-10-12T15:16:39Z
Modified
2026-10-14T02:47:46Z
Severity
  • 9.2 (Critical) CVSS_V4 - 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 Calculator
Summary
Square Squash through commit e73f280 Unauthenticated YAML Deserialization via Symbolication API
Details

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.

Database specific 
{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-502"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109391.json"
}
References

Affected packages

Git / github.com/SquareSquash/web

Affected ranges

Type
GIT
Repo
https://github.com/SquareSquash/web
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Last Affected
e73f2805f9eb30780a5c213b001f0f4255660fbf

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-109391.json"