# CVE-2026-28413: Products.isurlinportal: Possible open redirect when using more than 2 forward slashes

> Attackers can redirect users to external sites after login via crafted URLs with multiple slashes, affecting Plone users.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Mar 2026
- **Updated:** 6 Mar 2026
- **Also known as:** GHSA-43gx-6gv6-3jcp, PYSEC-2026-112

## What is CVE-2026-28413?

CVE-2026-28413 is a medium-severity vulnerability in plone Products.isurlinportal, published on 5 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Products.isurlinportal is a replacement for isURLInPortal method in Plone. Prior to versions 2.1.0, 3.1.0, and 4.0.0, a url /login?came_from=////evil.example may redirect to an external website after login. This issue has been patched in versions 2.1.0, 3.1.0, and 4.0.0.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2026-28413?

9 open source packages ship an affected version, including Products.isurlinportal and products-isurlinportal. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Products.isurlinportal` | PyPI | All versions | 2.1.0 |
| `Products.isurlinportal` | PyPI | From 3.0.0 | 3.1.0 |
| `Products.isurlinportal` | PyPI | From 4.0.0a1 | 4.0.0 |
| `products-isurlinportal` | PyPI | All versions | 2.1.0, 3.1.0 |
| `products-isurlinportal` | PyPI | All versions | 2.1.0 |
| `products-isurlinportal` | PyPI | All versions | 2.1.0 |
| `products-isurlinportal` | PyPI | From 3.0.0 | 3.1.0 |
| `products-isurlinportal` | PyPI | From 3.0.0 | 3.1.0 |
| `products-isurlinportal` | PyPI | From 4.0.0a1 | 4.0.0 |

Products: Plone Isurlinportal.

## How do I fix CVE-2026-28413?

Upgrade Products.isurlinportal to a fixed version for your release line: 2.1.0, 3.1.0 or 4.0.0.

## Is CVE-2026-28413 being exploited?

There is no known exploitation of CVE-2026-28413 in the wild and no public exploit code.

## Other vulnerabilities in plone Products.isurlinportal

- [CVE-2021-32806](https://insights.sbomify.com/CVE-2021-32806/): URL Redirection to Untrusted Site ('Open Redirect') in Products.isurlinportal (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-28413 and fix it if it is affected.

What it is: CVE-2026-28413 is a medium-severity vulnerability in plone Products.isurlinportal, published on 5 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-28413 in the wild and no public exploit code.

Affected packages and fixed versions:
- Products.isurlinportal (PyPI): affected all versions; fixed in 2.1.0
- Products.isurlinportal (PyPI): affected from 3.0.0; fixed in 3.1.0
- Products.isurlinportal (PyPI): affected from 4.0.0a1; fixed in 4.0.0
- products-isurlinportal (PyPI): affected all versions; fixed in 2.1.0, 3.1.0
- products-isurlinportal (PyPI): affected all versions; fixed in 2.1.0
- products-isurlinportal (PyPI): affected all versions; fixed in 2.1.0
- products-isurlinportal (PyPI): affected from 3.0.0; fixed in 3.1.0
- products-isurlinportal (PyPI): affected from 3.0.0; fixed in 3.1.0
- products-isurlinportal (PyPI): affected from 4.0.0a1; fixed in 4.0.0

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-2026-28413/ (Markdown: https://insights.sbomify.com/CVE-2026-28413/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28413
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28413
- OSV: https://osv.dev/vulnerability/CVE-2026-28413

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-28413/
Summaries are generated and may contain mistakes; the official description above is the record.