{"id":"UBUNTU-CVE-2026-12252","details":"In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept user-controllable JAR paths and execute them via the `java()` function, which invokes `subprocess.Popen()` without integrity verification. This vulnerability is identical to CVE-2026-0848, which was fixed for StanfordSegmenter by adding SHA256 verification. However, the fix was not applied to these additional classes, leaving them susceptible to arbitrary code execution when loading untrusted JAR files.","modified":"2026-07-09T15:15:45Z","published":"2026-07-04T02:16:00Z","upstream":["CVE-2026-12252"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-12252"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-12252"},{"type":"REPORT","url":"https://huntr.com/bounties/f5c93982-0cc9-4e2e-bb85-1b6ab29a2efb"}],"affected":[{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:14.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-infra-legacy%2Ftrusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0~b9-0ubuntu4","2.0~b9-0ubuntu4.1~esm2","2.0~b9-0ubuntu4.1~esm4","2.0~b9-0ubuntu4.1~esm5","2.0~b9-0ubuntu4.1~esm6"],"ecosystem_specific":{"binaries":[{"binary_version":"2.0~b9-0ubuntu4.1~esm6","binary_name":"python-nltk"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps-legacy%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.4-1","3.0.5-1","3.1-1","3.1-1ubuntu0.1","3.1-1ubuntu0.1+esm1","3.1-1ubuntu0.1+esm2","3.1-1ubuntu0.1+esm3","3.1-1ubuntu0.1+esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"python-nltk","binary_version":"3.1-1ubuntu0.1+esm4"},{"binary_name":"python3-nltk","binary_version":"3.1-1ubuntu0.1+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.2.4-1","3.2.5-1","3.2.5-1ubuntu0.1","3.2.5-1ubuntu0.1+esm1","3.2.5-1ubuntu0.1+esm2","3.2.5-1ubuntu0.1+esm3","3.2.5-1ubuntu0.1+esm4"],"ecosystem_specific":{"binaries":[{"binary_version":"3.2.5-1ubuntu0.1+esm4","binary_name":"python-nltk"},{"binary_name":"python3-nltk","binary_version":"3.2.5-1ubuntu0.1+esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Ffocal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.5-1","3.4.5-2","3.4.5-2ubuntu0.1~esm1","3.4.5-2ubuntu0.1~esm2","3.4.5-2ubuntu0.1~esm3","3.4.5-2ubuntu0.1~esm4"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-nltk","binary_version":"3.4.5-2ubuntu0.1~esm4"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fjammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.5-1","3.6.5-1","3.6.7-1","3.7-1","3.7-1ubuntu0.1~esm1","3.7-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-nltk","binary_version":"3.7-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:24.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fnoble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.8.1-1","3.8.1-1ubuntu0.1~esm1","3.8.1-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-nltk","binary_version":"3.8.1-1ubuntu0.1~esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9.1-2"],"ecosystem_specific":{"binaries":[{"binary_name":"python3-nltk","binary_version":"3.9.1-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}},{"package":{"name":"nltk","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/nltk?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.9.1-2","3.9.1-2build1","3.9.2-1","3.9.2-1ubuntu0.1~esm1","3.9.2-1ubuntu0.1~esm2"],"ecosystem_specific":{"binaries":[{"binary_version":"3.9.2-1ubuntu0.1~esm2","binary_name":"python3-nltk"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-12252.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}