High
nltk — security advisory
NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open(). Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting, including sensitive system files and application credentials.
- Products
- nltk
- Affected 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, 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, 3.10.0-1, 3.10.1-1, 3.10.3-1, 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, 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, 3.5-1, 3.6.5-1, 3.6.7-1, 3.7-1, 3.7-1ubuntu0.1~esm1, 3.7-1ubuntu0.1~esm2, 3.8.1-1, 3.8.1-1ubuntu0.1~esm1, 3.8.1-1ubuntu0.1~esm2, 3.9.1-2, 3.9.1-2build1, 3.9.2-1, 3.9.2-1ubuntu0.1~esm1, 3.9.2-1ubuntu0.1~esm2, 3.9.3-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-63312
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:11 UTC · Revision 1
Source evidence
NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open(). Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting, including sensitive system files and application credentials.
osv:UBUNTU-CVE-2026-63312
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
Complete source record
{
"id": "481194224d449ea0949c5a167309841f1a219c883f08c033d3e59ae134e59c10",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-63312",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-63312",
"summary": "NLTK before 3.10.0 contains an arbitrary local file read vulnerability in StreamBackedCorpusView that bypasses pathsec.ENFORCE by calling builtins.open() directly instead of pathsec.open(). Attackers who control the fileid argument can read arbitrary local files regardless of the ENFORCE setting, including sensitive system files and application credentials.",
"evidence": "osv:UBUNTU-CVE-2026-63312",
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},
{
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"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
},
{
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{
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{
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},
{
"value": "3.6.5-1",
"evidence": "/affected/4/versions"
},
{
"value": "3.6.7-1",
"evidence": "/affected/4/versions"
},
{
"value": "3.7-1",
"evidence": "/affected/4/versions"
},
{
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{
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"evidence": "/affected/5/versions"
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},
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{
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"evidence": "/affected/6/versions"
},
{
"value": "3.10.0-1",
"evidence": "/affected/6/versions"
},
{
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},
{
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{
"name": {
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},
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{
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"evidence": "/affected/7/versions"
},
{
"value": "3.9.1-2build1",
"evidence": "/affected/7/versions"
},
{
"value": "3.9.2-1",
"evidence": "/affected/7/versions"
},
{
"value": "3.9.2-1ubuntu0.1~esm1",
"evidence": "/affected/7/versions"
},
{
"value": "3.9.2-1ubuntu0.1~esm2",
"evidence": "/affected/7/versions"
}
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}
],
"severity": "high",
"structured": {
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"aliases": [
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],
"metrics": [
{
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"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
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{
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{
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},
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"3.0.5-1",
"3.1-1",
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"3.1-1ubuntu0.1+esm2",
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],
"database_specific": {
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},
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{
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],
"modified": "2026-10-17T13:00:31.854387901Z",
"provider": "osv",
"upstream": [
"CVE-2026-63312"
],
"references": [
"https://ubuntu.com/security/CVE-2026-63312",
"https://www.cve.org/CVERecord?id=CVE-2026-63312",
"https://github.com/nltk/nltk/security/advisories/ghsa-x5ph-mj9p-rfr8",
"https://security-tracker.debian.org/tracker/cve-2026-63312",
"https://github.com/cveproject/cvelistv5/tree/main/cves/2026/63xxx/cve-2026-63312.json",
"https://nvd.nist.gov/vuln/detail/cve-2026-63312",
"https://www.vulncheck.com/advisories/nltk-streambackedcorpusview-bypasses-pathsec-enforce-arbitrary-file-read"
]
},
"related_cves": [
{
"value": "CVE-2026-63312",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360659,
"published_at": "2026-08-22T15:16:00+00:00"
}