CVE-2026-33580
OpenClaw < 2026.3.28 - Brute Force Attack via Missing Rate Limiting on Webhook Shared Secret Authentication
OpenClaw before 2026.3.28 contains a missing rate limiting vulnerability in the Nextcloud Talk webhook authentication that allows attackers to brute-force weak shared secrets. Attackers who can reach the webhook endpoint can exploit this to forge inbound webhook events by repeatedly attempting authentication without throttling.
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
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
OpenClaw < 2026.3.28 - Brute Force Attack via Missing Rate Limiting on Webhook Shared Secret Authentication
OpenClaw before 2026.3.28 contains a missing rate limiting vulnerability in the Nextcloud Talk webhook authentication that allows attackers to brute-force weak shared secrets. Attackers who can reach the webhook endpoint can exploit this to forge inbound webhook events by repeatedly attempting authentication without throttling.
- Record
CVE-2026-33580- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-307
- Updated
- 2026-11-02
EUVDEUVD-2026-17439
OpenClaw before 2026.3.28 contains a missing rate limiting vulnerability in the Nextcloud Talk webhook authentication that allows attackers to brute-force weak shared secrets. Attackers who can reach the webhook endpoint can exploit this to forge inbound webhook events by repeatedly attempting authentication without throttling.
- Record
EUVD-2026-17439- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9528-x887-j2fp No score
OpenClaw's Nextcloud Talk webhook missing rate limiting on shared secret authentication
Summary
Nextcloud Talk webhook signature failures were not throttled even though the integration relies on an operator-configured shared secret that may be weak.
Impact
An attacker who could reach the webhook endpoint could brute-force weak secrets online and then forge inbound webhook events.
Affected Component
extensions/nextcloud-talk/src/monitor.ts
Fixed Versions
- Affected:
<= 2026.3.24 - Patched:
>= 2026.3.28 - Latest stable
2026.3.28contains the fix.
Fix
Fixed by commit e403decb6e (nextcloud-talk: throttle repeated webhook auth failures).
OpenClaw thanks @AntAISecurityLab for reporting.
- Record
GHSA-9528-x887-j2fp- Weakness
- CWE-307
- Updated
- 2026-11-02
NVD
OpenClaw before 2026.3.28 contains a missing rate limiting vulnerability in the Nextcloud Talk webhook authentication that allows attackers to brute-force weak shared secrets. Attackers who can reach the webhook endpoint can exploit this to forge inbound webhook events by repeatedly attempting authentication without throttling.
- Record
CVE-2026-33580- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/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
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-307
- Updated
- 2026-11-02
OSV
OpenClaw < 2026.3.28 - Brute Force Attack via Missing Rate Limiting on Webhook Shared Secret Authentication
OpenClaw before 2026.3.28 contains a missing rate limiting vulnerability in the Nextcloud Talk webhook authentication that allows attackers to brute-force weak shared secrets. Attackers who can reach the webhook endpoint can exploit this to forge inbound webhook events by repeatedly attempting authentication without throttling.
- Record
CVE-2026-33580- CVSS 4.0
- 6.3 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-307
- Updated
- 2026-11-02
OSVGHSA-9528-x887-j2fp No score
OpenClaw's Nextcloud Talk webhook missing rate limiting on shared secret authentication
Summary
Nextcloud Talk webhook signature failures were not throttled even though the integration relies on an operator-configured shared secret that may be weak.
Impact
An attacker who could reach the webhook endpoint could brute-force weak secrets online and then forge inbound webhook events.
Affected Component
extensions/nextcloud-talk/src/monitor.ts
Fixed Versions
- Affected:
<= 2026.3.24 - Patched:
>= 2026.3.28 - Latest stable
2026.3.28contains the fix.
Fix
Fixed by commit e403decb6e (nextcloud-talk: throttle repeated webhook auth failures).
OpenClaw thanks @AntAISecurityLab for reporting.
- Record
GHSA-9528-x887-j2fp- Weakness
- CWE-307
- 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-2026-33580 is a medium vulnerability (CVSS 6.3) in Openclaw, published March 31, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 31st percentile. Fixed in openclaw 2026.3.28.
References
github.com/openclaw/openclaw/security/advisories/GHSA-9528-x887-j2fp
vulncheck.com/advisories/openclaw-brute-force-attack-via-missing-rate-limiting-on-webhook-shared-secret-authentication
nvd.nist.gov/vuln/detail/CVE-2026-33580