Is there a public exploit for CVE-2026-78680?

No public exploit for CVE-2026-78680 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-78680?

CVE-2026-78680 scores CVSS 8.5 (v4.0), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.18%.

What does CVE-2026-78680 affect?

CVE-2026-78680 affects nltk nltk.

8.5 High

NLTK versions before 3.10.3 fail to use validated absolute paths when invoking the Graphviz dot binary in dependencygraph.dot2img and…

CVE-2026-78680

Two NLTK sites executed the Graphviz dot program by bare name, so process creation resolved it via the search path — and on Windows via the current working directory — rather than a validated absolute location. An attacker who can place a file named dot where resolution looks (the CWD on Windows, or a writable/relative entry such as . on PATH) has their binary executed in place of Graphviz (arbitrary code execution). Affected ( LookupError (refused) safe Attack 2: ./dot/dot (dir 'dot' holding 'dot') -> LookupError (refused) safe Attack 3: '.' on PATH + ./dot -> LookupError (refused) safe Attack 4: attacker-writable ABSOLUTE dir on PATH -> returned /…/evilbin/dot (absolute) Attack 4 is out of scope: trusting an absolute directory that is already on PATH is the operating system's own trust model — an attacker who can write to a PATH directory owns the account regardless of NLTK. findbinary defends specifically against the CWD/relative injection that bare-name exec is vulnerable to (attacks 1–3), which is exactly what this fix inherits. Environment: python 3.13.7. dot is not required to reproduce — the planted binary is the payload.

Assessment

CVSS: 8.5 (v4.0)
Severity: High
EPSS: 0.18% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 25 August 2026
Last updated: 12 October 2026
Affected: nltk · nltk · nltk
Weakness: CWE-426, CWE-427
Assigner: disclosure@vulncheck.com

CVSS vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

At the source

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