# CVE-2026-32726: SciTokens C++: Sibling-Path Authorization Bypass

> Attackers can bypass path-based authorization checks in SciTokens C++ by exploiting prefix matching flaws, gaining unauthorized access to sibling resources.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Mar 2026
- **Updated:** 31 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-32726, GHSA-q5fm-fgvx-32jq, UBUNTU-CVE-2026-32726

## What is CVE-2026-32726?

CVE-2026-32726 is a high-severity authentication bypass vulnerability in scitokens-cpp, published on 31 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

SciTokens C++ is a minimal library for creating and using SciTokens from C or C++. Prior to version 1.4.1, scitokens-cpp is vulnerable to an authorization bypass in path-based scope validation. The enforcer used a simple string-prefix comparison when checking whether a requested resource path was covered by a token's authorized scope path. Because the check did not require a path-segment boundary, a token scoped to one path could incorrectly authorize access to sibling paths that merely started with the same prefix. This issue has been patched in version 1.4.1.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-32726?

It affects 1 product.


Products: Scitokens Scitokens Cpp Library.

## How do I fix CVE-2026-32726?

Upgrade to a fixed version.

## Is CVE-2026-32726 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32726 exists.

## Other vulnerabilities in scitokens-cpp

- [CVE-2026-32725](https://insights.sbomify.com/CVE-2026-32725/): SciTokens C++: Relative Path Traversal Vulnerability (high 8.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32726 and fix it if it is affected.

What it is: CVE-2026-32726 is a high-severity authentication bypass vulnerability in scitokens-cpp, published on 31 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32726 exists.

Affected product: scitokens-cpp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-32726/ (Markdown: https://insights.sbomify.com/CVE-2026-32726/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32726
- OSV: https://osv.dev/vulnerability/CVE-2026-32726

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32726/
Summaries are generated and may contain mistakes; the official description above is the record.