Which versions of OpenClaw Nextcloud Talk are affected by CVE-2026-28474?

OpenClaw's Nextcloud Talk plugin versions 2026.2.2 and earlier contain a critical authentication bypass that allows unauthenticated attackers to impersonate allowlisted users and access restricted…. A patch is available.

How to fix or mitigate CVE-2026-28474?

Within 24 hours: Identify all Nextcloud instances running OpenClaw Talk plugin version 2026.2.2 or earlier and assess current user access logs for suspicious display name changes. Within 7 days: Apply vendor patch to upgrade all affected instances to version 2026.2.6 or later. Within 30 days: Conduct audit of restricted room and DM access logs from the past 90 days to identify any unauthorized access via spoofed display names, and reset access permissions for any compromised communication channels.

OpenClaw Nextcloud Talk CVE-2026-28474

Q: What is the CVSS score of CVE-2026-28474?

CVE-2026-28474 has a CVSS 4.0 base score of 9.3 (Critical). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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. EPSS exploitation probability: 0.1%.

CRITICAL

Incorrect Authorization (CWE-863)

2026-03-05 disclosure@vulncheck.com

GHSA-r5h9-vjqc-hq3r

Authentication Bypass Nextcloud

9.3

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

9.3 CRITICAL

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Source Code Evidence Fetched

May 06, 2026 - 14:58 vuln.today

Analysis Updated

May 06, 2026 - 14:58 vuln.today

v2 (cvss_changed)

Re-analysis Queued

May 06, 2026 - 14:52 vuln.today

cvss_changed

CVSS changed

May 06, 2026 - 14:52 NVD

9.8 (CRITICAL) 9.3 (CRITICAL)

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 22:06 vuln.today

CVE Published

Mar 05, 2026 - 22:16 nvd

CRITICAL 9.8

DescriptionCVE.org

OpenClaw's Nextcloud Talk plugin versions prior to 2026.2.6 accept equality matching on the mutable actor.name display name field for allowlist validation, allowing attackers to bypass DM and room allowlists. An attacker can change their Nextcloud display name to match an allowlisted user ID and gain unauthorized access to restricted conversations.

AnalysisAI

Authentication bypass in OpenClaw's Nextcloud Talk plugin versions ≤2026.2.2 allows remote unauthenticated attackers to bypass DM and room allowlists by spoofing display names. Attackers can change their Nextcloud display name to match an allowlisted user ID, gaining unauthorized access to restricted conversations without authentication. EPSS score is low (0.05%, 16th percentile), indicating low observed exploitation probability. No active exploitation confirmed; vulnerability was responsibly disclosed by AISLE Research Team and patched in version 2026.2.6.

Technical ContextAI

The vulnerability stems from improper authorization (CWE-863) in the @openclaw/nextcloud-talk npm package. Nextcloud Talk webhooks provide two actor identifiers: actor.id (stable, immutable user ID) and actor.name (mutable display name controlled by the user). The flawed implementation performed allowlist validation using string equality matching against both fields. Because actor.name is user-controlled and can be changed at will through Nextcloud's profile settings, attackers could set their display name to match any allowlisted user ID string. The policy.ts module's resolveNextcloudTalkAllowlistMatch function treated display names as trusted identifiers equivalent to actual user IDs. The fix removes all senderName parameters from allowlist validation logic, ensuring only the immutable actor.id field is checked. This is a classic confused deputy problem where the system trusted attacker-controllable input (display name) as if it were a verified identity claim (user ID).

RemediationAI

Upgrade the @openclaw/nextcloud-talk package to version 2026.2.6 or later via npm (npm install @openclaw/nextcloud-talk@latest). The patch commit 6b4b6049b47c3329a7014509594647826669892d removes display name matching from allowlist validation logic, ensuring only immutable actor.id fields are checked. Organizations unable to upgrade immediately should remove allowlist-based access controls and temporarily switch to open access or alternative authentication mechanisms until patching is complete, accepting the trade-off of reduced granular access control. Do not attempt to block specific display names as a workaround-the vulnerability is architectural and cannot be mitigated through configuration. Review conversation access logs for the period between January 20, 2026 (vulnerability introduction) and patch deployment to identify potential unauthorized access; look for actor.name values matching allowlisted user IDs where actor.id differs. Vendor advisory: https://github.com/openclaw/openclaw/security/advisories/GHSA-r5h9-vjqc-hq3r. VulnCheck advisory: https://www.vulncheck.com/advisories/openclaw-nextcloud-talk-allowlist-bypass-via-actorname-display-name-spoofing.