CriticalFix available
nltk — security advisory
NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.
- Products
- nltk
- Affected versions
- 3.10.0-1, 3.10.1-1, 3.10.3-1, 3.8-1, 3.8.1-1, 3.9.1-1, 3.9.1-2, 3.9.2-1, 3.9.3-1
- Fixed versions
- 3.10.3-1
- CVEs
- CVE-2026-79657
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 11:06 UTC · Revision 1
Source evidence
NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.
osv:DEBIAN-CVE-2026-79657
nltk
Fixed versions: Not specified
nltk
Fixed versions: Not specified
nltk
Fixed versions: 3.10.3-1
Complete source record
{
"id": "90c03ed862fab58352b1b3c26abc68b8f4248c0cf8ecad18c060d7ae1c689b8c",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-79657",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-79657",
"summary": "NLTK versions before 3.10.3 contain a remote code execution vulnerability in allowlisted pickle loaders that trust entire module namespaces instead of specific safe callables. Attackers can craft malicious pickle payloads invoking dangerous in-namespace functions like ReppTokenizer._execute and numpy.f2py.crackfortran.myeval through pickle REDUCE to execute arbitrary commands during model or tokenizer artifact loading.",
"evidence": "osv:DEBIAN-CVE-2026-79657",
"products": [
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},
"prerequisites": [],
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{
"value": "3.10.0-1",
"evidence": "/affected/0/versions"
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{
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"evidence": "/affected/0/versions"
},
{
"value": "3.10.3-1",
"evidence": "/affected/0/versions"
},
{
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{
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{
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{
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{
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{
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{
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{
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],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2026-79657",
"aliases": [
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],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"affected": [
{
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{
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"events": [
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],
"package": {
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"purl": "pkg:deb/debian/nltk?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
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"3.9.1-1",
"3.9.1-2",
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"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-79657.json"
},
"ecosystem_specific": {
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}
},
{
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"package": {
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"ecosystem": "Debian:13"
},
"versions": [
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"3.10.1-1",
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"3.9.3-1"
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"database_specific": {
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},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
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{
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],
"package": {
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"purl": "pkg:deb/debian/nltk?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
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"3.10.1-1",
"3.9.1-2",
"3.9.2-1",
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},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-09T09:47:23.076164214Z",
"provider": "osv",
"upstream": [
"CVE-2026-79657"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-79657"
]
},
"related_cves": [
{
"value": "CVE-2026-79657",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 111420,
"published_at": "2026-08-25T12:16:28.87+00:00"
}