{"id":"CVE-2026-12243","title":"nltk: NLTK: Information disclosure via path traversal vulnerability (CVE-2026-12243)","summary":"A flaw was found in NLTK. An attacker can exploit a path traversal vulnerability by providing specially crafted input to `nltk.data.load()` or `nltk.data.find()`. This allows the attacker to read arbitrary files accessible to the Python pr…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cvssSource":"vendor","cwe":"CWE-22","vendor":"Red Hat","product":"Red Hat OpenShift AI 3.4","affected":["exploit_intelligence","ansible_automation_platform 2","openshift_ai_rhoai","openshift_ai 2.25","openshift_ai 3.4"],"patched":["openshift_ai 2.25","openshift_ai 3.4"],"published":"2026-06-30","updated":"2026-09-08","sourceUpdated":"2026-09-08T21:52:26+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12243.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12243.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-12243"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2494748"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-12243"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-12243"},{"url":"https://huntr.com/bounties/39aa9354-54ca-4e77-96da-580eb1fe6ed1"},{"url":"https://access.redhat.com/errata/RHSA-2026:65126"},{"url":"https://access.redhat.com/errata/RHSA-2026:60520"},{"url":"https://github.com/nltk/nltk/security/advisories/GHSA-m42h-3232-vpv3"},{"url":"https://github.com/nltk/nltk/issues/3504"},{"url":"https://github.com/nltk/nltk/pull/3522"},{"url":"https://github.com/nltk/nltk/commit/aec4fce1b84ad725b8975f7365b23a4f626572a9"},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-597.yaml"},{"url":"https://securityinfinity.com/research/path-traversal-in-nltks-nltk-data-load-via-percent-encoded-sequences"},{"url":"https://github.com/advisories/GHSA-m42h-3232-vpv3"}],"tags":["csaf","vex","red-hat","exploit-available","ghsa","pip"],"exploits":{"github":1,"githubRepos":["https://github.com/morzelowski/CVE-2026-12243-NLTK-PoC"],"checkedAt":"2026-09-09T03:23:21.292Z"},"exploitAvailable":true,"aliases":["GHSA-m42h-3232-vpv3"],"ecosystem":"pip","ingestedAt":"2026-08-13T21:07:31.849Z","slug":"CVE-2026-12243","body":"## Overview\n\nA flaw was found in NLTK. An attacker can exploit a path traversal vulnerability by providing specially crafted input to `nltk.data.load()` or `nltk.data.find()`. This allows the attacker to read arbitrary files accessible to the Python process, leading to information disclosure. The vulnerability arises from an incomplete fix that fails to account for percent-encoded traversal sequences.\n\n## Vendor advisories\n\n- **RHSA-2026:65126** · Red Hat · fixed in: Red Hat OpenShift AI 2.25 · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:65126)\n- **RHSA-2026:60520** · Red Hat · fixed in: Red Hat OpenShift AI 3.4 · released 2026-08-27 · [advisory](https://access.redhat.com/errata/RHSA-2026:60520)\n- **Red Hat VEX** · Important · affected: Exploit Intelligence, Red Hat Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI) · no fix planned: Red Hat Ansible Automation Platform 2, Exploit Intelligence, Red Hat OpenShift AI (RHOAI) · updated 2026-09-08 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-12243.json)\n\n**nltk: NLTK: Information disclosure via path traversal vulnerability** — rated Important by Red Hat. Released 2026-06-30, updated 2026-09-08.\n\nAffected:\n\n- Exploit Intelligence\n- Red Hat Ansible Automation Platform 2\n- Red Hat OpenShift AI (RHOAI)\n\nFixed:\n\n- Red Hat OpenShift AI 2.25\n- Red Hat OpenShift AI 3.4\n\nNo fix planned:\n\n- Red Hat Ansible Automation Platform 2\n- Exploit Intelligence\n- Red Hat OpenShift AI (RHOAI)\n\nNot affected:\n\n- Red Hat OpenShift AI 2.25\n- Red Hat OpenShift AI 3.4\n- OpenShift Lightspeed\n- Red Hat OpenShift AI (RHOAI)\n\n## Remediation\n\nFor Red Hat OpenShift AI 2.25.11 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:\n\nhttps://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:65126\nFor Red Hat OpenShift AI 3.4.4 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update:\n\nhttps://docs.redhat.com/en/documentation/red_hat_openshift_ai/ https://access.redhat.com/errata/RHSA-2026:60520\n\nWorkarounds / mitigations:\n\n- Do not pass untrusted or user-controlled input directly to nltk.data.load() or nltk.data.find(). Validate and sanitize any resource name parameter before use, rejecting values containing percent-encoded characters (%2f, %2e) or path traversal sequences. As defense-in-depth, set nltk.pathsec.ENFORCE = True in application code to enable file-read restrictions at the open stage (disabled by default).\n\n## Package advisory (CVE-2026-12243)\n\nAffected packages:\n\n- `nltk < 3.10.0`\n\nPatched in:\n\n- `nltk 3.10.0`\n\nSource: https://github.com/advisories/GHSA-m42h-3232-vpv3","depth":"midnight","depthScore":53,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":4938,"id":"CVE-2026-12243","ts":1788887217870,"field":"exploit_available","old":"false","new":"true"},{"seq":3821,"id":"CVE-2026-12243","ts":1788886349679,"field":"exploit_available","old":"true","new":"false"},{"seq":2659,"id":"CVE-2026-12243","ts":1788883015400,"field":"exploit_available","old":"false","new":"true"},{"seq":1688,"id":"CVE-2026-12243","ts":1788882419383,"field":"exploit_available","old":"true","new":"false"},{"seq":796,"id":"CVE-2026-12243","ts":1788881853196,"field":"exploit_available","old":"false","new":"true"}]}