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MEDIUM severity

CVE-2026-28413 — products-isurlinportal

MEDIUM

CVE-2026-28413 is a medium-severity (CVSS 5.3) Open Redirect vulnerability in products-isurlinportal. A fix is available for products-isurlinportal — see the affected versions and patch details below.

Products.isurlinportal: Possible open redirect when using more than 2 forward slashes

Also known asGHSA-43gx-6gv6-3jcpPYSEC-2026-112
Published
Updated
Affected
5 pkgs
Patched
5 / 5
Exploits
None indexed
Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-28413.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk
0.00%0.25%0.51%0.76%0.0%0.3%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

5 pkgs affected
🐍products-isurlinportal🐍products-isurlinportal🐍products-isurlinportal🐍products-isurlinportal🐍products-isurlinportal

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

A url /login?came_from=////evil.example may redirect to an external website after login.

Standard Plone is not affected, but if you have customised the login, for example with add-ons, you might be affected. You can try the url to check if you are affected or not.

Patches

The problem has been patched in Products.isurlinportal.

  • Plone 6.2: upgrade to Products.isurlinportal 4.0.0.
  • Plone 6.1: upgrade to Products.isurlinportal 3.1.0.
  • Plone 6.0: upgrade to Products.isurlinportal 2.1.0.
  • Older Plone versions don't have security support anymore.

Workarounds

There are no known workarounds.

Background

When you are anonymous and land on a page that requires a login, Plone sends you to the login form. After successful login, Plone redirects you back to the page you came from. Various other forms and pages have a similar system.

This could get abused by an attacker to trick Plone into redirecting to a different website. Plone checks the page that would be redirected to. It is only accepted if it is within the Plone site domain or part of a different trusted domain.

The main check for this is in the Products.isurlinportal package. A lot of potentially malicious urls are already safely rejected, but here a loop hole was found.

This was discovered during a penetration test by the CERT-EU Team.

Affected Packages

5 total 5 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIproducts-isurlinportal≥ 4.0.0a1&&< 4.0.04.0.0pip install --upgrade 'products-isurlinportal==4.0.0'
🐍PyPIproducts-isurlinportal≥ 3.0.0&&< 3.1.03.1.0pip install --upgrade 'products-isurlinportal==3.1.0'
🐍PyPIproducts-isurlinportalall versions2.1.0pip install --upgrade 'products-isurlinportal==2.1.0'
🐍PyPIproducts-isurlinportalall versions2.1.0pip install --upgrade 'products-isurlinportal==2.1.0'
🐍PyPIproducts-isurlinportal≥ 3.0.0&&< 3.1.03.1.0pip install --upgrade 'products-isurlinportal==3.1.0'

Affected Products

1 product · 3 configurations
Application
isurlinportalplone
≥ 3.0.0 && < 3.1.0
1 version
4.0.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for products-isurlinportal, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update products-isurlinportal to 4.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-28413 is resolved across your whole dependency graph.

  3. Workarounds

    Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Frequently Asked Questions

### Impact A url `/login?came_from=////evil.example` may redirect to an external website after login. Standard Plone is not affected, but if you have customised the login, for example with add-ons, you might be affected. You can try the url to check if you are affected or not. ### Patches The problem has been patched in `Products.isurlinportal`. * Plone 6.2: upgrade to `Products.isurlinportal` 4.0.0. * Plone 6.1: upgrade to `Products.isurlinportal` 3.1.0. * Plone 6.0: upgrade to `Products.isurlinportal` 2.1.0. * Older Plone versions don't have security support anymore. ### Workarounds Ther
O3 Security · Impact-Aware SCA

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CVE-2026-28413: products-isurlinportal — Fixed in 4.0.0