Medium severity6.9NVD Advisory· Published Mar 26, 2021· Updated Jun 17, 2026
CVE-2021-21332
CVE-2021-21332
Description
Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.27.0, the password reset endpoint served via Synapse was vulnerable to cross-site scripting (XSS) attacks. The impact depends on the configuration of the domain that Synapse is deployed on, but may allow access to cookies and other browser data, CSRF vulnerabilities, and access to other resources served on the same domain or parent domains. This is fixed in version 1.27.0.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
matrix-synapsePyPI | < 1.27.0 | 1.27.0 |
Affected products
4cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*range: <1.27.0
- (no CPE)range: < 1.27.0
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
Patches
Vulnerability mechanics
References
9- github.com/matrix-org/synapse/commit/e54746bdf7d5c831eabe4dcea76a7626f1de73dfnvdPatchThird Party AdvisoryWEB
- github.com/matrix-org/synapse/pull/9200nvdPatchThird Party AdvisoryWEB
- github.com/advisories/GHSA-246w-56m2-5899ghsaADVISORY
- github.com/matrix-org/synapse/releases/tag/v1.27.0nvdThird Party AdvisoryWEB
- github.com/matrix-org/synapse/security/advisories/GHSA-246w-56m2-5899nvdThird Party AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2021-21332ghsaADVISORY
- github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2021-133.yamlghsaWEB
- lists.fedoraproject.org/archives/list/[email protected]/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEYghsaWEB
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/nvd
News mentions
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