CVE-2018-16515 json
Matrix Synapse Improper Signature Validation
published 8y ago modified 4mo ago also GHSA-fmvh-rvq5-hhjx , PYSEC-2026-845 , EUVD-2022-3811
- cvss
- 8.8
- version 3.0, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.5%
- EPSS 1.5% chance of exploitation in 30 days, percentile 75%
- public exploits
- 0
- none known
Summary
Matrix Synapse before 0.33.3.1 allows remote attackers to spoof events and possibly have unspecified other impacts by leveraging improper transaction and event signature validation.
Patch / fix
- pypi matrix-synapse 0.33.2.1, 0.33.3.1
- matrix synapse 0.33.3.1
- matrix-synapse Ubuntu Pro 18.04 LTS 0.24.0+dfsg-1ubuntu0.1~esm1
ubuntu advisories UBUNTU-CVE-2018-16515
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
Is CVE-2018-16515 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerVendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2018-16515 updated
matrix-synapse: pre-disclosure of critical vulnerability
-
Red Hat All currently supported Red Hat productsnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
1.54% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.0 | 8.8 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 6.5 | AV:N/AC:L/Au:S/C:P/I:P/A:P |
| OSV | 3.0 | 8.8 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.0 | 8.8 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | matrix-synapse | >=0.33.3, <0.33.3.1 <0.33.2.1 |
0.33.3.1 0.33.2.1 |
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
-
github.com
/matrix-org/synapse/issues/3796#event-1833126269
web, patch, third-party-advisory
-
github.com
/matrix-org/synapse/commit/5bf8bc79ebc22c61968f2eb487714813fccbdb9b
web
-
github.com
/matrix-org/synapse/commit/804dd41e18c449e711e443398b95c9f6c68b6fa2
web
-
github.com
/matrix-org/synapse/commit/a5a0bf5cf71caed3c4e3677d2bce667c147dadfc
web
-
github.com
/matrix-org/synapse/commit/c127c8d0421f0228a46ebbe280c9537e8d8ea42b
web
-
lists.fedoraproject.org
/archives/list/package-announce%40lists.fedoraproject.org/message/IRW7YR2H3ASUSYX4AO4KMY3FNVDNYW3P/
vendor-advisory
-
matrix.org
/blog/2018/09/06/critical-security-update-synapse-0-33-3-1/
vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2018-16515
advisory
-
github.com
/matrix-org/synapse
package
-
lists.fedoraproject.org
/archives/list/package-announce@lists.fedoraproject.org/message/IRW7YR2H3ASUSYX4AO4KMY3FNVDNYW3P
web
-
matrix.org
/blog/2018/09/06/critical-security-update-synapse-0-33-3-1
web
-
pypi.org
/project/matrix-synapse
package
-
github.com
/advisories/GHSA-fmvh-rvq5-hhjx
advisory
Sources
- CVE List CVE-2018-16515
- GitHub Advisory GHSA-fmvh-rvq5-hhjx
- NVD CVE-2018-16515
- OSV PYSEC-2026-845
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.