CVE-2026-46671: Rust OneNote File Parser Path Traversal Vulnerability

MODERATE
Advisory Identifier: GHSA-4j5m-wc25-pvh7
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CVSS 4.4
CWE-22
Published
Advisory Summary

CVE-2026-46671 is a MODERATE (CVSS 4.4) path traversal vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Rust OneNote File Parser libraries in the crates.io ecosystem. The issue involves path traversal in `parser::parse_notebook` allows reading files outside the notebook directory. Remediation is available by upgrading affected packages to version 1.1.1.

CVE-2026-46671 at a Glance

CVE Identifier CVE-2026-46671
GHSA Identifier GHSA-4j5m-wc25-pvh7
Severity MODERATE
CVSS v3.1 Base Score 4.4
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Rust OneNote File Parser
Package Ecosystem crates.io
Published Date
Last Updated

Security Impact

CVSS: 4.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-46671

To remediate this vulnerability, upgrade all affected Rust OneNote File Parser dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

onenote_parser fixed: 1.1.1 
Upgrade onenote_parser to 1.1.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for onenote_parser

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-46671, inspect your project dependencies for Rust OneNote File Parser:

inspect dependencies for onenote_parser

Analyze the terminal output to locate any version of Rust OneNote File Parser in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.1.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Rust OneNote File Parser, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact A maliciously crafted `.onetoc2` table-of-contents file can cause `Parser::parse_notebook` 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 `onenote_parser` 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 onenote_parser 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 confirm it stays inside the notebook's base directory. ### Workarounds For users who cannot upgrade to 1.1.1: - Only call `Parser::parse_notebook` on `.onetoc2` files from trusted sources. - Alternatively, use `Parser::parse_section` / `Parser::parse_section_buffer` on individual .one files, which do not perform the directory walk.

CVE-2026-46671 Affected Rust OneNote File Parser Versions

1 component(s)
Fixed Versions:
1.1.1
Product / Package Ecosystem Affected Versions Fixed Version
onenote_parser
 crates.io
< 1.1.1
1.1.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/msiemens/onenote.rs/security/advisories/GHSA-4j5m-wc25-pvh7
Security Fix Commit FIX COMMIT
https://github.com/msiemens/onenote.rs/commit/c9267b2c96e2542be7e7b557d67318e81b733585
Rust OneNote File Parser Source Repository REPOSITORY
https://github.com/msiemens/onenote.rs
Rust OneNote File Parser Source Repository REPOSITORY
https://github.com/msiemens/onenote.rs/blob/master/CHANGELOG.md#111---2026-05-15
Rust OneNote File Parser Release RELEASE
https://github.com/msiemens/onenote.rs/releases/tag/v1.1.1

Frequently Asked Questions

What is CVE-2026-46671?
CVE-2026-46671 is a security vulnerability in Rust OneNote File Parser involving Path traversal in `Parser::parse_notebook` allows reading files outside the notebook directory under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Rust OneNote File Parser versions are affected?
Affected versions include releases prior to 1.1.1 across affected packages: onenote_parser.
What version fixes CVE-2026-46671?
Upgrading to 1.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is onenote_parser affected?
Yes, onenote_parser is affected in releases prior to 1.1.1. Upgrade your dependency to 1.1.1 or later.
What is the CVSS score of CVE-2026-46671?
CVE-2026-46671 has a CVSS v3.1 base score of 4.4 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L.
What CWE is associated with CVE-2026-46671?
CVE-2026-46671 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check crates.io dependencies for CVE-2026-46671?
Run the dependency tree command: 'inspect dependencies for onenote_parser'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4j5m-wc25-pvh7",
  "modified" : "2026-05-21T21:32:11Z",
  "published" : "2026-05-21T21:32:11Z",
  "aliases" : [ "CVE-2026-46671" ],
  "summary" : "Rust OneNote File Parser: Path traversal in `Parser::parse_notebook` allows reading files outside the notebook directory",
  "details" : "### Impact\nA maliciously crafted `.onetoc2` table-of-contents file can cause `Parser::parse_notebook` 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.\n\nThe 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.\n\nAnyone using `onenote_parser` to parse .onetoc2 files received from untrusted sources is affected. Users who only ever parse their own notebooks are not at meaningful risk.\n\n### Patches\nFixed in onenote_parser 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 confirm it stays inside the notebook's base directory.\n\n### Workarounds\nFor users who cannot upgrade to 1.1.1:\n\n- Only call `Parser::parse_notebook` on `.onetoc2` files from trusted sources.\n- Alternatively, use `Parser::parse_section` / `Parser::parse_section_buffer` on individual .one files, which do not perform the directory walk.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "onenote_parser"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.1.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/msiemens/onenote.rs/security/advisories/GHSA-4j5m-wc25-pvh7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/msiemens/onenote.rs/commit/c9267b2c96e2542be7e7b557d67318e81b733585"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/msiemens/onenote.rs"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/msiemens/onenote.rs/blob/master/CHANGELOG.md#111---2026-05-15"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/msiemens/onenote.rs/releases/tag/v1.1.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-21T21:32:11Z",
    "nvd_published_at" : null
  }
}