CVE-2026-28449

OpenClaw < 2026.2.25 - Webhook Replay Attack via Missing Durable Replay Suppression

Published Mar 19, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed

Description

OpenClaw versions prior to 2026.2.25 lack durable replay state for Nextcloud Talk webhook events, allowing valid signed webhook requests to be replayed without suppression. Attackers can capture and replay previously valid signed webhook requests to trigger duplicate inbound message processing and cause integrity or availability issues.

Analysis

Technical impact

OpenClaw versions earlier than 2026.2.25 lack a durable replay state for Nextcloud Talk webhook events, allowing an attacker to capture a valid signed webhook payload and replay it without suppression. This results in duplicate inbound message processing, which can corrupt data integrity or disrupt availability of the messaging service. The weakness is identified as CWE-294, Improper Handling of Reset or Replay Conditions.

Affected Systems

All OpenClaw installations running any version before 2026.2.25 are affected. The vulnerability applies to the OpenClaw:OpenClaw product as represented by the CPE string cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*.

Risk and Exploitability

The CVSS score of 6.3 indicates moderate severity. No EPSS score is available and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector involves an adversary able to intercept or otherwise obtain a previously valid signed webhook request and replay it at a later time. No additional privileges are required beyond the ability to capture the request, making exploitation straightforward and potentially harmful for systems that rely on webhook integrity.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

OpenClaw

unaffected

Version	Status	Constraints
`0`	affected	< 2026.2.25

Configuration 1 [-]

cpe:2.3:a:openclaw:openclaw:*:*:*:*:*:node.js:*:*

No data.

Vendor Product Versions

Openclaw

Version	Status	Scheme	Platform
`[0,2026.2.25)`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Apply the official OpenClaw patch 2026.2.25 or later.
If a patch cannot be applied immediately, disable or remove unused webhook endpoints to prevent replay of captured requests.
Monitor webhook traffic for duplicate events and investigate any unexpected repetitions.

Generated by OpenCVE AI on March 19, 2026 at 03:21 UTC.

Tracking

Advisories

Source	ID	Title
Github GHSA	GHSA-r9q5-c7qc-p26w	OpenClaw's Nextcloud Talk webhook replay could trigger duplicate inbound processing

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.310% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://github.com/openclaw/openclaw/commit/d512163d686ad6741783e7119ddb3437f493dbbc
https://github.com/openclaw/openclaw/security/advisories/GHSA-r9q5-c7qc-p26w
https://www.vulncheck.com/advisories/openclaw-webhook-replay-attack-via-missing-durable-replay-suppression

History

Apr 29, 2026 3:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics	ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`	ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Mar 25, 2026 3:00 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics	cvssV3_1 `{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'}`	cvssV3_1 `{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'}`

Mar 19, 2026 5:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Mar 19, 2026 1:30 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		OpenClaw versions prior to 2026.2.25 lack durable replay state for Nextcloud Talk webhook events, allowing valid signed webhook requests to be replayed without suppression. Attackers can capture and replay previously valid signed webhook requests to trigger duplicate inbound message processing and cause integrity or availability issues.
Title		OpenClaw < 2026.2.25 - Webhook Replay Attack via Missing Durable Replay Suppression
First Time appeared		Openclaw Openclaw openclaw
Weaknesses		CWE-294
CPEs		cpe:2.3:a:openclaw:openclaw::::::node.js::*
Vendors & Products		Openclaw Openclaw openclaw
References		https://github.com/openclaw/openclaw/commit/d512163d686ad6741783e7119ddb3437f493dbbc https://github.com/openclaw/openclaw/security/advisories/GHSA-r9q5-c7qc-p26w https://www.vulncheck.com/advisories/openclaw-webhook-replay-attack-via-missing-durable-replay-suppression
Metrics		cvssV3_1 `{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'}` cvssV4_0 `{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}`