How severe is CVE-2004-1177?

No CVSS score has been assigned to CVE-2004-1177 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2004-1177?

CVE-2004-1177 affects the following packages: mailman (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2004-1177?

Update mailman to 2.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2004-1177 is resolved across your whole dependency graph.

How do I detect CVE-2004-1177 in my PyPI dependencies?

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

How do I mitigate CVE-2004-1177 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-2004-1177 actively exploited in the wild?

No public exploit code has been indexed for CVE-2004-1177 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-2004-1177?

CVE-2004-1177 has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 79th 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.

When was CVE-2004-1177 published, and has it been updated?

CVE-2004-1177 was published on April 29, 2022 and was last updated on July 6, 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

CVE-2004-1177 — mailman

CVE-2004-1177 is a security vulnerability in mailman. A fix is available for mailman — see the affected versions and patch details below.

mailman Cross-site scripting (XSS) vulnerability

Also known asPYSEC-2026-659

Published

Apr 29, 2022

Updated

Jul 6, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

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

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs79th percentile — riskier than 79% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

🐍mailman

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

Cross-site scripting (XSS) vulnerability in the driver script in mailman before 2.1.5 allows remote attackers to inject arbitrary web script or HTML via a URL, which is not properly escaped in the resulting error page.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`mailman`	all versions	2.1.5`pip install --upgrade 'mailman==2.1.5'`

Affected Products

1 product · 25 configurations

Application

mailmangnu

22 versions

1.01.12.02.0.12.0.22.0.32.0.42.0.52.0.62.0.72.0.82.0.9

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mailman, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mailman to 2.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2004-1177 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.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatImportant

This issue did not affect the versions of mailman shipped with Red Hat Enterprise Linux 2.1, 3, or 4. In addition, we believe this issue does not apply to the 2.0.x versions of mailman due to setting of STEALTH_MODE

Product	Fixed in	Advisory
Red Hat Enterprise Linux 3	`mailman-3:2.1.5-25.rhel3`	RHSA-2005:235

Frequently Asked Questions

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