{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-109391 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-109391 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-109391 is a critical unsafe deserialization vulnerability in Square Squash, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-109391 and fix it if it is affected.\n\nWhat it is: CVE-2026-109391 is a critical unsafe deserialization vulnerability in Square Squash, published on 12 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-109391 in the wild and no public exploit code.\n\nAffected product: Square Squash. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-109391/ (Markdown: https://insights.sbomify.com/CVE-2026-109391/index.md)","id":"CVE-2026-109391","markdown":"https://insights.sbomify.com/CVE-2026-109391/index.md","name":"CVE-2026-109391","record":{"aliases":["GHSA-f7j3-hchq-qp35"],"analysis":{"component_type":"web_application","fix_type":"patch","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Squash error reporting","requires_auth":"none","summary":"Unauthenticated attackers can achieve remote code execution in Square Squash by submitting malicious YAML payloads to the symbolication API.","user_interaction":"not_required","vuln_class":"deserialization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":9.2,"severity":"critical","source":"cna","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","version":"4.0"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"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.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"Square Squash through commit e73f280 Unauthenticated YAML Deserialization via Symbolication API","id":"CVE-2026-109391","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"deserialization","year":"2026"},"n_packages":0,"n_references":7,"next":{"headline":"Pimcore through 2026.3.1 Stored XSS via ExternalImage Field Version Preview","id":"CVE-2026-109392"},"packages":[],"prev":{"headline":"Memory corruption in AnyDesk","id":"CVE-2026-109390"},"products":["Squash"],"published":"2026-10-12","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-27","vendors":["Square"]},"summary":"Unauthenticated attackers can achieve remote code execution in Square Squash by submitting malicious YAML payloads to the symbolication API.","url":"https://insights.sbomify.com/CVE-2026-109391/"}