CVE-2026-41399
OpenClaw < 2026.3.28 - Denial of Service via Unbounded Pre-auth WebSocket Upgrades
OpenClaw before 2026.3.28 accepts unbounded concurrent unauthenticated WebSocket upgrades without pre-authentication budget allocation. Unauthenticated network attackers can exhaust socket and worker capacity to disrupt WebSocket availability for legitimate clients.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
OpenClaw < 2026.3.28 - Denial of Service via Unbounded Pre-auth WebSocket Upgrades
OpenClaw before 2026.3.28 accepts unbounded concurrent unauthenticated WebSocket upgrades without pre-authentication budget allocation. Unauthenticated network attackers can exhaust socket and worker capacity to disrupt WebSocket availability for legitimate clients.
- Record
CVE-2026-41399- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2026-26107
OpenClaw before 2026.3.28 accepts unbounded concurrent unauthenticated WebSocket upgrades without pre-authentication budget allocation. Unauthenticated network attackers can exhaust socket and worker capacity to disrupt WebSocket availability for legitimate clients.
- Record
EUVD-2026-26107- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-f44p-c7w9-7xr7
OpenClaw: Gateway WebSocket Denial of Service via unbounded pre-auth upgrades
Summary
The gateway accepted unbounded concurrent unauthenticated WebSocket upgrades before allocating them to an authenticated session budget.
Impact
An unauthenticated network attacker could consume socket and worker capacity and disrupt WebSocket availability for legitimate clients.
Affected Component
src/gateway/server-http.ts, src/gateway/server/preauth-connection-budget.ts
Fixed Versions
- Affected:
<= 2026.3.24 - Patched:
>= 2026.3.28 - Latest stable
2026.3.28contains the fix.
Fix
Fixed by commit cb5f7e201f (gateway: cap concurrent pre-auth websocket upgrades).
Discovered by：Topsec AlphaLab (wang dong)
- Record
GHSA-f44p-c7w9-7xr7- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
NVD
OpenClaw before 2026.3.28 accepts unbounded concurrent unauthenticated WebSocket upgrades without pre-authentication budget allocation. Unauthenticated network attackers can exhaust socket and worker capacity to disrupt WebSocket availability for legitimate clients.
- Record
CVE-2026-41399- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSV
OpenClaw < 2026.3.28 - Denial of Service via Unbounded Pre-auth WebSocket Upgrades
OpenClaw before 2026.3.28 accepts unbounded concurrent unauthenticated WebSocket upgrades without pre-authentication budget allocation. Unauthenticated network attackers can exhaust socket and worker capacity to disrupt WebSocket availability for legitimate clients.
- Record
CVE-2026-41399- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-770
- Updated
- 2026-11-02
OSVGHSA-f44p-c7w9-7xr7
OpenClaw: Gateway WebSocket Denial of Service via unbounded pre-auth upgrades
Summary
The gateway accepted unbounded concurrent unauthenticated WebSocket upgrades before allocating them to an authenticated session budget.
Impact
An unauthenticated network attacker could consume socket and worker capacity and disrupt WebSocket availability for legitimate clients.
Affected Component
src/gateway/server-http.ts, src/gateway/server/preauth-connection-budget.ts
Fixed Versions
- Affected:
<= 2026.3.24 - Patched:
>= 2026.3.28 - Latest stable
2026.3.28contains the fix.
Fix
Fixed by commit cb5f7e201f (gateway: cap concurrent pre-auth websocket upgrades).
Discovered by：Topsec AlphaLab (wang dong)
- Record
GHSA-f44p-c7w9-7xr7- CVSS 4.0
- 5.3 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-41399 is a high vulnerability (CVSS 8.7) in Openclaw, published March 31, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.32%, the 24th percentile. Fixed in openclaw 2026.3.28.
References
github.com/openclaw/openclaw/security/advisories/GHSA-f44p-c7w9-7xr7
vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-pre-auth-websocket-upgrades
nvd.nist.gov/vuln/detail/CVE-2026-41399