CVE-2019-16935 — The documentation XML-RPC server in Python through 2

The documentation XML-RPC server in Python through 2.7.16, 3.x through 3.6.9, and 3.7.x through 3.7.4 has XSS via the server_title field. This occurs in Lib/DocXMLRPCServer.py in Python 2.x, and in Lib/xmlrpc/server.py in Python 3.x. If set_server_title is called with untrusted i

01What is this vulnerability?

The documentation XML-RPC server in Python through 2.7.16, 3.x through 3.6.9, and 3.7.x through 3.7.4 has XSS via the server_title field. This occurs in Lib/DocXMLRPCServer.py in Python 2.x, and in Lib/xmlrpc/server.py in Python 3.x. If set_server_title is called with untrusted input, arbitrary JavaScript can be delivered to clients that visit the http URL for this server.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2019-09-28T02:15:10.463
• Last modified: 2026-10-07T19:17:12.787

09References

• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00062.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-10/msg00063.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00012.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00021.html
• lists.opensuse.org — http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
• bugs.python.org — https://bugs.python.org/issue38243
• github.com — https://github.com/python/cpython/blob/35c0809158be7feae4c4f877a08b93baea2d8291/…
• github.com — https://github.com/python/cpython/blob/e007860b8b3609ce0bc62b1780efaa06241520bd/…
• github.com — https://github.com/python/cpython/pull/16373
• lists.debian.org — https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html