CVE-2026-81726: NLTK · Model-artifact APIs bypass pathsec and touch files outside allowed roots
Affects safetySource GCVE Database
Not known to be exploited · CVSS 7.0 High : upgrade to 3.8.1_3 soon.
Data as of 27 Oct 2026, 06:43 UTC
- Patch
- Available – fixed in 3.8.1_3
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 2 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade safety to 3.8.1_3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewsafetypkg:brew/safetyOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in NLTK version 3.8.1_3. Users should upgrade to this version or later. The remediation involves routing all model-path file access through nltk.pathsec.open() or other pathsec-aware helpers and adding regression tests to ensure pathsec enforcement is effective. Until patched, avoid using untrusted input for model import/export paths with pathsec enabled.
Description
NLTK contains a file sandbox bypass vulnerability in several model-artifact APIs that use raw file operations on caller-controlled paths, bypassing path security enforcement. This allows reading or writing files outside of allowed root directories despite pathsec restrictions. The flaw affects versions from 3.7.0_7 up to but not including 3.8.1_3. A patch is available in version 3.8.1_3.
References
- github.com/nltk/nltk/security/advisories/GHSA-8mgp-746c-j5xp (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-81726 (opens in a new tab)
- github.com/nltk/nltk/pull/3757 (opens in a new tab)
- github.com/nltk/nltk/pull/3759 (opens in a new tab)
- github.com/nltk/nltk/pull/3813 (opens in a new tab)
- github.com/nltk/nltk/commit/2a92b71827d754ae8920261e7ed0c4bb283ab2d7 (opens in a new tab)
- github.com/nltk/nltk/commit/a44a7af69bca87e92d9c4a701fcbbe4512e8d450 (opens in a new tab)
- github.com/nltk/nltk/commit/cbc98458b43de5f792f0382583c16df39e5c5117 (opens in a new tab)
- github.com/nltk/nltk (opens in a new tab)
- github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3740.yaml (opens in a new tab)
- vulncheck.com/advisories/nltk-through-3.10.3-path-traversal-via-model-artifact-apis (opens in a new tab)