CVE-2026-65915: nltk Improper Access Control
Vulnerability summary
CVE-2026-65915 is a high (CVSS 7.1) Improper Access Control vulnerability in nltk. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 33.8% of scored vulnerabilities. 1 public exploit is recorded.
Timeline
- 22-08-2026PublishedVulnerability first disclosed.
- 24-08-2026Last modifiedVulnerability information updated.
Description
NLTK versions before 3.10.0 contain a logic bug in FileSystemPathPointer.open() where the sandbox validation check compares a normalized path against itself, making the security check permanently inert. Attackers can pass file:// URLs to nltk.data.load() to read arbitrary files accessible to the process user, including credentials and configuration files.
CVSS metrics
8 scores · 5 sources · 2 versions- OSV · PypiEcosystem advisory · calculated7.1HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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
- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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
- NVDNIST7.1HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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
- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- NVDNIST6.5MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.41%
Chance of exploitation in the next 30 days
Percentile
34%
Versus all other CVEs
30-day change
+0.05 pp
From 0.36% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundNltk
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Debian1 product
- nltkAll versions (No fix recorded) | < 3.10.0-1
Nltk1 product
- nltk< 3.10.0
PyPI1 product
- nltk< 3.10.0
Ubuntu1 product
- nltkAll versions (No fix recorded)
4 vendors · 4 products
References
15 links- www.vulncheck.com/advisories/nltk-before-arbitrary-file-read-via-filesystempathpointerThird Party AdvisoryWEBAdvisoryREPORT
- github.com/nltk/nltkPACKAGE
