NLTK 3.9.4 Path Traversal via FrameNet and NKJP Readers
Noroxi assessment
Priority: Monitor (action score 32/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.42% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: nltk nltk 3.10.0.
Low priority for now. Upgrade to nltk nltk 3.10.0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
NLTK versions before 3.10.0 contain a path traversal vulnerability in FramenetCorpusReader and NKJPCorpusReader that allows attackers to parse XML files outside the corpus root by supplying unsafe selectors or poisoned index state. Attackers can exploit frame_by_name, doc, lu, and header methods with crafted parameters to read arbitrary XML files accessible to the application.
- Published
- Aug 22, 2026
- Updated
- Oct 14, 2026
- EPSS
- 0.4% · 35th percentile
- CWE
- CWE-73
Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.2 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 8.2
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| nltk | nltk | cpe:2.3:a:nltk:nltk |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nltk nltkbefore 3.10.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
nltk nltk
- 3.10.0not affected
- before 3.10.0affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | nltk | from 0 | — |
| Debian:14 | nltk | before 3.10.0-1 | 3.10.0-1 |
| PyPI | nltk | before 3.10.0 | 3.10.0 |
Same product
nltk: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-0848Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading40Plan
- CVE-2026-79675NLTK before 3.10.3 JVM Argument Injection via Per-Call Options37Monitor
- CVE-2026-79657NLTK before 3.10.3 Remote Code Execution via Unsafe Pickle Deserialization37Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-62383Aug 22, 2026 · nltk IPIPANCorpusReader Symlink Arbitrary File Read27Monitor
- ← EarlierCVE-2026-62384Aug 22, 2026 · NLTK FramenetCorpusReader Symlink Sandbox Bypass before 3.10.234Monitor
- Later →CVE-2026-62388Aug 22, 2026 · NLTK before 3.10.0 Insecure Default Configuration in pathsec.py34Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| nltk nltk | 3.10.0 | Vendor (CNA) |
| debian:nltk | 3.10.0-1 · Debian:14 | Package registry (OSV) |
| PyPI:nltk | 3.10.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-796743 days apartNLTK 3.10.2 Path Traversal via corpus-reader constructors35Monitor
- CVE-2026-817265 days apartNLTK through 3.10.3 Path Traversal via Model-Artifact APIs33Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-73 · External Control of File Name or PathCVSS vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/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
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Leverage Alternate EncodingCAPEC-267likelihood: High · High
- Using Slashes and URL Encoding Combined to Bypass Validation LogicCAPEC-64likelihood: High · High
- URL EncodingCAPEC-72likelihood: High · High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
- Using Escaped Slashes in Alternate EncodingCAPEC-78likelihood: High · High
- Using Slashes in Alternate EncodingCAPEC-79likelihood: High · High
- Using UTF-8 Encoding to Bypass Validation LogicCAPEC-80likelihood: High · High
Change log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.