ChatterBot: Symlink-Following Arbitrary Write via UbuntuCorpusTrainer

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.5 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-58198: 0.14% estimated exploitation activity in the next 30 days; percentile 3.29 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary ChatterBot's UbuntuCorpusTrainer.extract() uses a predictable, home-rooted output directory (~/ubuntudata/ubuntudialogs) with a check-then-create pattern (if not os.path.exists: os.makedirs) followed by tar.extractall(path=self.datapath). A local attacker who pre-plants a symlink at the predictable path causes os.path.exists() to return True (following the symlink), skipping makedirs, and subsequent extractall writes archive contents through the symlink to the attacker-chosen directory. The existing safeextract function validates tar member names (zip-slip defense) but does not validate the output directory itself — it cannot detect that self.datapath is a symlink. This is the defining distinction between the archiveextraction (zip-slip) and insecurefscreatetoctou families. Vulnerability Details Predictable output directory (line 535-546) Check-then-create (line 621-622) Extraction through symlink (line 633-644) safeextract calls os.path.abspath(directory) on self.datapath —…

Published by the source

19 Jun 2026, 22:08 UTC

Last modified by the source

10 Jul 2026, 04:11 UTC

Source last checked

26 Oct 2026, 13:46 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-wvrh-2f4m-924v

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-wvrh-2f4m-924v

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# Patch Next advisory brief: CVE-2026-58198

Advisory: ChatterBot: Symlink-Following Arbitrary Write via UbuntuCorpusTrainer
IDs: CVE-2026-58198, GHSA-wvrh-2f4m-924v
Record: https://patchnext.com/advisories/cve-2026-58198 (revision 2, source checked 26 Oct 2026, 13:46 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: chatterbot 1.2.14. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI chatterbot: affected <= 1.2.13; fixed in 1.2.14

## Suggested inspection (read-only)
- `python -m pip show chatterbot`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on chatterbot.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-wvrh-2f4m-924v (OSV record GHSA-wvrh-2f4m-924v lists affected ranges: PyPI chatterbot >=0 <1.2.14 (fixed))
- Verified: https://github.com/advisories/GHSA-wvrh-2f4m-924v (GitHub-reviewed advisory GHSA-wvrh-2f4m-924v lists affected ranges: PyPI chatterbot >=0 <=1.2.13)

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