CVE-2026-62384
NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.65%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
NLTK versions before 3.10.2 contain a symlink-based sandbox bypass in FramenetCorpusReader that allows attackers to read arbitrary XML files outside the corpus root. Attackers can place symlinks with names containing no path separators inside the corpus subdirectory, which pass the path validation guard and are resolved to files outside the intended corpus root when accessed via frame_by_name(), _lu_file(), or doc() methods.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/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/M
- EPSS
- 0.65% probability · 51th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-22
- Affected
- nltk/nltk
- Source
- disclosure@vulncheck.com
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/nltk/nltk/security/advisories/GHSA-f833-7jw8-xwrvExploit, Vendor Advisory
- https://www.vulncheck.com/advisories/nltk-framenetcorpusreader-symlink-sandbox-bypass-beforeThird Party Advisory
- https://github.com/nltk/nltk/security/advisories/GHSA-f833-7jw8-xwrvExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.