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+Synapse 1.23.1 (2020-12-09)
+===========================
+
+Due to the two security issues highlighted below, server administrators are
+encouraged to update Synapse. We are not aware of these vulnerabilities being
+exploited in the wild.
+
+Security advisory
+-----------------
+
+The following issues are fixed in v1.23.1 and v1.24.0.
+
+- There is a denial of service attack
+ ([CVE-2020-26257](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26257))
+ against the federation APIs in which future events will not be correctly sent
+ to other servers over federation. This affects all servers that participate in
+ open federation. (Fixed in [#8776](https://github.com/matrix-org/synapse/pull/8776)).
+
+- Synapse may be affected by OpenSSL
+ [CVE-2020-1971](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1971).
+ Synapse administrators should ensure that they have the latest versions of
+ the cryptography Python package installed.
+
+To upgrade Synapse along with the cryptography package:
+
+* Administrators using the [`matrix.org` Docker
+ image](https://hub.docker.com/r/matrixdotorg/synapse/) or the [Debian/Ubuntu
+ packages from
+ `matrix.org`](https://github.com/matrix-org/synapse/blob/master/INSTALL.md#matrixorg-packages)
+ should ensure that they have version 1.24.0 or 1.23.1 installed: these images include
+ the updated packages.
+* Administrators who have [installed Synapse from
+ source](https://github.com/matrix-org/synapse/blob/master/INSTALL.md#installing-from-source)
+ should upgrade the cryptography package within their virtualenv by running:
+ ```sh
+ <path_to_virtualenv>/bin/pip install 'cryptography>=3.3'
+ ```
+* Administrators who have installed Synapse from distribution packages should
+ consult the information from their distributions.
+
+Bugfixes
+--------
+
+- Fix a bug in some federation APIs which could lead to unexpected behaviour if different parameters were set in the URI and the request body. ([\#8776](https://github.com/matrix-org/synapse/issues/8776))
+
+
+Internal Changes
+----------------
+
+- Add a maximum version for pysaml2 on Python 3.5. ([\#8898](https://github.com/matrix-org/synapse/issues/8898))
+
+
Synapse 1.23.0 (2020-11-18)
===========================
|
