SciTokens has an Authorization Bypass via Path Traversal in Scope Validation

Exploitation

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

CVSS

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

EPSS

• CVE-2026-32727: 0.53% estimated exploitation activity in the next 30 days; percentile 44.55 (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 The Enforcer is vulnerable to a path traversal attack where an attacker can use dot-dot (..) in the scope claim of a token to escape the intended directory restriction. This occurs because the library normalizes both the authorized path (from the token) and the requested path (from the application) before comparing them using startswith. Details File: src/scitokens/scitokens.py Methods: checkscope, scopepathmatches File: src/scitokens/urltools.py Method: normalizepath Description When a token is verified, the Enforcer extracts the authorized path from the scope or scp claim. This path is passed through urltools.normalizepath, which uses posixpath.normpath to resolve relative segments. If a token has a scope like read:/home/user1/.., the normalization process converts this to /home. When the enforcer checks if a request for /home/user2 is authorized, it compares it against the normalized path /home. Vulnerable Logic Flow: 1. Normalization: In checkscope, the path…

Published by the source

31 Mar 2026, 22:51 UTC

Last modified by the source

13 Jul 2026, 07:26 UTC

Source last checked

26 Oct 2026, 13:40 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-3x2w-63fp-3qvw

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-3x2w-63fp-3qvw

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# Patch Next advisory brief: CVE-2026-32727

Advisory: SciTokens has an Authorization Bypass via Path Traversal in Scope Validation
IDs: CVE-2026-32727, GHSA-3x2w-63fp-3qvw
Record: https://patchnext.com/advisories/cve-2026-32727 (revision 2, source checked 26 Oct 2026, 13:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: scitokens 1.9.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI scitokens: affected < 1.9.7; fixed in 1.9.7

## Suggested inspection (read-only)
- `python -m pip show scitokens`: 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 scitokens.
- 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-3x2w-63fp-3qvw (OSV record GHSA-3x2w-63fp-3qvw lists affected ranges: PyPI scitokens >=0 <1.9.7 (fixed))
- Verified: https://github.com/advisories/GHSA-3x2w-63fp-3qvw (GitHub-reviewed advisory GHSA-3x2w-63fp-3qvw lists affected ranges: PyPI scitokens >=0 <1.9.7)

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