How severe is CVE-2024-45399?

CVE-2024-45399 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2024-45399?

CVE-2024-45399 affects the following packages: indico (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2024-45399?

Update indico to 3.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-45399 is resolved across your whole dependency graph.

How do I detect CVE-2024-45399 in my PyPI dependencies?

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

How do I mitigate CVE-2024-45399 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2024-45399 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-45399 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2024-45399?

CVE-2024-45399 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 33th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2024-45399?

CVE-2024-45399 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2024-45399 published, and has it been updated?

CVE-2024-45399 was published on September 4, 2024 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2024-45399 — indico

MEDIUMFix: indico/flask-multipass@0bdcf65

CVE-2024-45399 is a medium-severity (CVSS 4.3) Cross-site Scripting (XSS) vulnerability in indico. A fix is available for indico — see the affected versions and patch details below.

Indico has a Cross-Site-Scripting during account creation

Also known asGHSA-rrqf-w74j-24ffPYSEC-2024-90

Published

Sep 4, 2024

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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-2024-45399.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

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

1 pkg affected

🐍indico

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

There is a Cross-Site-Scripting vulnerability during account creation when redirecting after the account has been successfully created. Exploitation requires the user to initiate the account creation process with a maliciously crafted link, and then finalize the signup process. Because of this, it can only target newly created (and thus unprivileged) Indico users so the benefits of exploiting it are very limited.

Patches

You should to update to Indico 3.3.4 as soon as possible. See the docs for instructions on how to update.

Workarounds

If you build the Indico package yourself and cannot upgrade for some reason, you can simply update the flask-multipass dependency to >=0.5.5 which fixes the vulnerability. You would do that by editing requirements.txt before building the package (see commit 7dcb573837), or possibly cherry-picking that particular commit.
Otherwise you could configure your web server to disallow requests containing a query string with a parameter that starts with javascript:

For more information

If you have any questions or comments about this advisory:

Open a thread in our forum
Email us privately at [email protected]

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`indico`	all versions	3.3.4`pip install --upgrade 'indico==3.3.4'`

Affected Products

1 product · 1 configurations

Application

indicocern

< 3.3.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for indico, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update indico to 3.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-45399 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact There is a Cross-Site-Scripting vulnerability during account creation when redirecting after the account has been successfully created. Exploitation requires the user to initiate the account creation process with a maliciously crafted link, and then finalize the signup process. Because of this, it can only target newly created (and thus unprivileged) Indico users so the benefits of exploiting it are very limited. ### Patches You should to update to [Indico 3.3.4](https://github.com/indico/indico/releases/tag/v3.3.4) as soon as possible. See [the docs](https://docs.getindico.io/en/s