matrix-synapse vulnerable to temporary storage of plaintext passwords during password changes
Impact
When users update their passwords, the new credentials may be briefly held in the server database. While this doesn't grant the server any added capabilities—it already learns the users' passwords as part of the authentication process—it does disrupt the expectation that passwords won't be stored in the database. As a result, these passwords could inadvertently be captured in database backups for a longer duration.
These temporarily stored passwords are automatically erased after a 48-hour window.
Patches
https://github.com/matrix-org/synapse/pull/16272
References
This bug was due to a regression in https://github.com/matrix-org/synapse/pull/13188.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | matrix-synapse | >= 1.66.0, < 1.93.0 | 1.93.0 |
References
- https://github.com/matrix-org/synapse/pull/16272
- https://github.com/matrix-org/synapse/security/advisories/GHSA-4f74-84v3-j9q5
- https://nvd.nist.gov/vuln/detail/CVE-2023-41335
- https://github.com/matrix-org/synapse/pull/13188
- https://github.com/matrix-org/synapse/commit/69b74d9330e42fc91a9c7423d00a06cd6d3732bf
- https://github.com/matrix-org/synapse
- https://github.com/pypa/advisory-database/tree/main/vulns/matrix-synapse/PYSEC-2023-185.yaml
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2AFB2Y3S2VCPCN5P2XCZTG24MBMZ7DM4
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/65QPC55I4D27HIZP7H2NQ34EOXHPP4AO
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/N6P4QULVUE254WI7XF2LWWOGHCYVFXFY
- https://security.gentoo.org/glsa/202401-12
- CVSS vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:N- Weakness (CWE)
CWE-312- Platform
- Python (PyPI)
- Package
matrix-synapse- Disclosed
- 26.09.2023
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2023-185 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-4f74-84v3-j9q5 - CC BY 4.0
Vulnerability history: matrix-synapse
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 45
- First → latest
- 03.2019 05.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 21
- Medium 21
- Low 3
Disclosures per year
- 2019: 3
- 2020: 3
- 2021: 12
- 2022: 7
- 2023: 9
- 2024: 7
- 2025: 2
- 2026: 2
-
matrix-synapse vulnerable to temporary storage of plaintext passwords during password changes this entry
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