{"id":"UBUNTU-CVE-2025-56005","details":"An undocumented and unsafe feature in the PLY (Python Lex-Yacc) library 3.11 allows Remote Code Execution (RCE) via the `picklefile` parameter in the `yacc()` function. This parameter accepts a `.pkl` file that is deserialized with `pickle.load()` without validation. Because `pickle` allows execution of embedded code via `__reduce__()`, an attacker can achieve code execution by passing a malicious pickle file. The parameter is not mentioned in official documentation or the GitHub repository, yet it is active in the PyPI version. This introduces a stealthy backdoor and persistence risk. NOTE: A third-party states that this vulnerability should be rejected because the proof of concept does not demonstrate arbitrary code execution and fails to complete successfully.","modified":"2026-06-30T18:15:45.962232225Z","published":"2026-01-20T19:15:00Z","upstream":["CVE-2025-56005"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-56005"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-56005"},{"type":"REPORT","url":"https://github.com/bohmiiidd/Undocumented-RCE-in-PLY"}],"affected":[{"package":{"name":"ply","ecosystem":"Ubuntu:16.04:LTS","purl":"pkg:deb/ubuntu/ply?arch=source&distro=xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.7-1"],"ecosystem_specific":{"binaries":[{"binary_name":"python-ply","binary_version":"3.7-1"},{"binary_name":"python3-ply","binary_version":"3.7-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-56005.json"}},{"package":{"name":"ply","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/ply?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9-1","3.11-1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.11-1","binary_name":"python-ply"},{"binary_name":"python3-ply","binary_version":"3.11-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-56005.json"}},{"package":{"name":"ply","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/ply?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.11-3","3.11-3build1","3.11-3ubuntu0.1"],"ecosystem_specific":{"binaries":[{"binary_version":"3.11-3ubuntu0.1","binary_name":"python-ply"},{"binary_version":"3.11-3ubuntu0.1","binary_name":"python3-ply"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-56005.json"}},{"package":{"name":"ply","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/ply?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.11-4ubuntu1","3.11-5"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-ply","binary_version":"3.11-5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-56005.json"}},{"package":{"name":"ply","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/ply?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.11-5","3.11-6"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-ply","binary_version":"3.11-6"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-56005.json"}},{"package":{"name":"ply","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/ply?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.11-9"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-ply","binary_version":"3.11-9"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-56005.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}