Rust OneNote File Parser: Path traversal in Parser::parse_notebook allows reading files outside the notebook directory

Exploitation

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

CVSS

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

EPSS

• CVE-2026-46671: 0.15% estimated exploitation activity in the next 30 days; percentile 4.39 (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.

Impact A maliciously crafted .onetoc2 table-of-contents file can cause Parser::parsenotebook to open arbitrary files on the host filesystem outside the notebook's directory. The parser reads entry names listed inside the .onetoc2 and joins them against the notebook's base directory without validating that they are relative paths confined to that directory. The parser will bail out when the target file fails to parse as a OneNote section, so direct content exfiltration through the parser's return value is not practical, though file-existence probing and denial-of-service via large or special files remain possible. Anyone using onenoteparser to parse .onetoc2 files received from untrusted sources is affected. Users who only ever parse their own notebooks are not at meaningful risk. Patches Fixed in onenoteparser 1.1.1. The fix rejects absolute paths, parent-directory components, and other invalid path characters in entry names, and additionally canonicalises the resolved path to…

Published by the source

21 May 2026, 21:32 UTC

Last modified by the source

21 May 2026, 21:32 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4j5m-wc25-pvh7

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# Patch Next advisory brief: CVE-2026-46671

Advisory: Rust OneNote File Parser: Path traversal in `Parser::parse_notebook` allows reading files outside the notebook directory
IDs: CVE-2026-46671, GHSA-4j5m-wc25-pvh7
Record: https://patchnext.com/advisories/cve-2026-46671 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: onenote_parser 1.1.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io onenote_parser: affected < 1.1.1; fixed in 1.1.1

## Suggested inspection (read-only)
- crates.io onenote_parser: check the installed version with your package manager.

## 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 onenote_parser.
- 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://github.com/advisories/GHSA-4j5m-wc25-pvh7 (GitHub-reviewed advisory GHSA-4j5m-wc25-pvh7 lists affected ranges: crates.io onenote_parser >=0 <1.1.1)

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