CVE-2026-45078— Synapse CPU starvation (Denial of Service)
Quick assessment
Affected
element-hq synapse
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
synapse是Element开源的一个矩阵主服务器。 synapse 1.152.1之前版本存在安全漏洞，该漏洞源于本地已认证用户可导致CPU资源耗尽，造成其他请求失败和拒绝服务。
Possible ATT&CK Techniques 1 AI
T1496 · Resource HijackingAffected Version Matrix 1
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| element-hq | synapse | < 1.152.1 |
affected |
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-45078
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Synapse CPU starvation (Denial of Service)
Source: CVE Program / CVE List V5
Vulnerability Description
Synapse is an open source Matrix homeserver implementation. Prior to 1.152.1, local authenticated users can cause Synapse to starve other requests of CPU and lead to other requests failing, causing other users to be denied service. This vulnerability is fixed in 1.152.1.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
不加限制或调节的资源分配
Source: CVE Program / CVE List V5
Vulnerability Title
synapse 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
synapse是Element开源的一个矩阵主服务器。 synapse 1.152.1之前版本存在安全漏洞，该漏洞源于本地已认证用户可导致CPU资源耗尽，造成其他请求失败和拒绝服务。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| element-hq | synapse | < 1.152.1 | - |
|
II. Public POCs for CVE-2026-45078
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-45078
请登录查看更多情报信息。
Vendor Advisories for CVE-2026-45078 (1)
IV. Related Vulnerabilities
Same product: synapse
-
CVE-2026-45076
Synapse pagination denial of service -
CVE-2025-61672
Synapse: Invalid device keys degrade federation functionalit -
CVE-2025-30355
Synapse vulnerable to federation denial of service via malfo -
CVE-2024-37303
Synapse unauthenticated writes to the media repository allow -
CVE-2024-37302
Synapse denial of service through media disk space consumpti
Same vendor: element-hq
-
CVE-2026-55850
Element Web: A malicious homeserver can inject HTML in Eleme -
CVE-2026-48007
Element Call reports full URLs of visited pages to analytics -
CVE-2026-45076
Synapse pagination denial of service -
CVE-2026-24044
ESS Community Helm Chart has a weak server key generation me -
CVE-2025-62425
Matrix Authentication Service account password can be change
Same weakness: CWE-770
-
CVE-2026-105127
LaraDashboard 1.4.2 before 1.4.8 Resource Exhaustion via Pas -
CVE-2026-97873
Legacy PBES1 and PKCS#12 PBE iteration count honoured unboun -
CVE-2026-104845
Seroval: Memory exhaustion via unchecked TypedArray length i -
CVE-2026-66054
Apache Thrift: C++ THeaderTransport does not enforce configu -
CVE-2026-61374
Apache Thrift: Java TSaslTransport post-auth data-frame miss
V. Comments for CVE-2026-45078
No comments yet