CVE-2026-28413 — products-isurlinportal
MEDIUMCVE-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
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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-28413 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
products-isurlinportal🐍products-isurlinportal🐍products-isurlinportal🐍products-isurlinportal🐍products-isurlinportalReal-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.isurlinportal4.0.0. - Plone 6.1: upgrade to
Products.isurlinportal3.1.0. - Plone 6.0: upgrade to
Products.isurlinportal2.1.0. - 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
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | products-isurlinportal | ≥ 4.0.0a1&&< 4.0.0 | 4.0.0pip install --upgrade 'products-isurlinportal==4.0.0' |
| 🐍PyPI | products-isurlinportal | ≥ 3.0.0&&< 3.1.0 | 3.1.0pip install --upgrade 'products-isurlinportal==3.1.0' |
| 🐍PyPI | products-isurlinportal | all versions | 2.1.0pip install --upgrade 'products-isurlinportal==2.1.0' |
| 🐍PyPI | products-isurlinportal | all versions | 2.1.0pip install --upgrade 'products-isurlinportal==2.1.0' |
| 🐍PyPI | products-isurlinportal | ≥ 3.0.0&&< 3.1.0 | 3.1.0pip install --upgrade 'products-isurlinportal==3.1.0' |
Detection & mitigation playbook
Open-source dependencyDetect
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.
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.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-28413 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-28413. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-28413 in your dependencies?
O3 Security finds CVE-2026-28413 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.