CVE-2026-28449

MEDIUM
Published March 19, 2026

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...

Full CISO analysis pending enrichment.

What systems are affected?

Package Ecosystem Vulnerable Range Patched
OpenClaw pip No patch
4 dependents 37% patched ~3d to patch Full package profile →

Do you use OpenClaw? You're affected.

How severe is it?

CVSS 3.1
6.5 / 10
EPSS
N/A
Exploitation Status
No known exploitation
Sophistication
N/A

What is the attack surface?

AV AC PR UI S C I A
AV Network
AC Low
PR None
UI None
S Unchanged
C None
I Low
A Low

What should I do?

No patch available

Monitor for updates. Consider compensating controls or temporary mitigations.

Which compliance frameworks are affected?

Compliance analysis pending. Sign in for full compliance mapping when available.

Frequently Asked Questions

What is CVE-2026-28449?

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.

Is CVE-2026-28449 actively exploited?

No confirmed active exploitation of CVE-2026-28449 has been reported, but organizations should still patch proactively.

How to fix CVE-2026-28449?

No patch is currently available. Monitor vendor advisories for updates.

What is the CVSS score for CVE-2026-28449?

CVE-2026-28449 has a CVSS v3.1 base score of 6.5 (MEDIUM).

What are the technical details?

Original Advisory

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.

Weaknesses (CWE)

CWE-294 — Authentication Bypass by Capture-replay: A capture-replay flaw exists when the design of the product makes it possible for a malicious user to sniff network traffic and bypass authentication by replaying it to the server in question to the same effect as the original message (or with minor changes).

  • [Architecture and Design] Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.
  • [Architecture and Design] Since any attacker who can listen to traffic can see sequence numbers, it is necessary to sign messages with some kind of cryptography to ensure that sequence numbers are not simply doctored along with content.

Source: MITRE CWE corpus.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Timeline

Published
March 19, 2026
Last Modified
June 23, 2026
First Seen
June 23, 2026

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