# CVE-2026-126295: NLTK 3.10.0 before 3.10.4 Arbitrary File Read via BllipParser Model Paths

Status: published. Published: 2026-11-13. Updated: 2026-11-13.

NLTK from 3.10.0 before 3.10.4 contains an arbitrary file read vulnerability in BllipParser that allows attackers to open files outside NLTK data roots by supplying unvalidated model paths. Attackers controlling parser_model, reranker_features, reranker_weights, or from_unified_model_dir() input can make the bllipparser C extension read sensitive files or block on FIFOs and devices.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- nltk / nltk (nltk): ≥ 3.10.0; < 3.10.4 (affected, semver); 3.10.4 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L; source: CNA: VulnCheck

- CVSS 4.0: 7 (high); CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:L/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; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-22

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/nltk/nltk/security/advisories/GHSA-fg9w-wfp5-j933 (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/nltk-3.10.0-before-3.10.4-arbitrary-file-read-via-bllipparser-model-paths (CNA: VulnCheck; third-party-advisory)

- https://github.com/nltk/nltk/security/advisories/GHSA-fg9w-wfp5-j933 (disclosure@vulncheck.com)

- https://www.vulncheck.com/advisories/nltk-3.10.0-before-3.10.4-arbitrary-file-read-via-bllipparser-model-paths (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-126295; retrieved 2026-11-13; source updated 2026-11-13

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126295; retrieved 2026-11-13; source updated 2026-11-13

Revision: 723a0cc802cb1859318d0b446fbc079b0b72721511519800d65e93fdb55aead1

Canonical: https://y2.dev/cve/CVE-2026-126295

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