CVE-2026-85621: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-627w-x4jq-g83v
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CVSS 6.5
CWE-345
Published
Advisory Summary

CVE-2026-85621 is a MODERATE (CVSS 6.5) security vulnerability vulnerability (CWE-345: Insufficient Verification of Data Authenticity) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-85621 at a Glance

CVE Identifier CVE-2026-85621
GHSA Identifier GHSA-627w-x4jq-g83v
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-345: Insufficient Verification of Data Authenticity
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-85621

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-85621, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-345: Insufficient Verification of Data Authenticity, where the product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

LobeChat (LobeHub) 2.2.1 does not properly verify inbound chat-platform webhook signatures in the QQ and Feishu adapters. The webhook route (/api/agent/webhooks/:platform) is unauthenticated by design and delegates verification to each adapter; the QQ adapter performs no Ed25519 signature verification on dispatched message events, and the Feishu adapter only performs an optional static-token comparison that is skipped when no token is configured (the default) and is not a body signature. An unauthenticated attacker who knows the public webhook URL can POST forged inbound messages with an attacker-chosen sender identity and arbitrary text, causing the bot owner's agent to process attacker-controlled input and treat the attacker as a trusted platform sender.

References

NVD — CVE-2026-85621 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-85621
Software Source Repository REPOSITORY
https://github.com/lobehub/lobehub/issues/16538
Software Source Repository REPOSITORY
https://github.com/lobehub/lobehub
Software Source Repository REPOSITORY
https://github.com/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-feishu/src/adapter.ts
Software Source Repository REPOSITORY
https://github.com/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-qq/src/adapter.ts
www.vulncheck.com/advisories/lobechat... WEB
https://www.vulncheck.com/advisories/lobechat-2.2.1-webhook-signature-verification-bypass-qq-feishu

Frequently Asked Questions

What is CVE-2026-85621?
CVE-2026-85621 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-345: Insufficient Verification of Data Authenticity.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-85621?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-85621?
CVE-2026-85621 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2026-85621?
CVE-2026-85621 is classified under CWE-345: Insufficient Verification of Data Authenticity (The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.).
How can I check Maven dependencies for CVE-2026-85621?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-627w-x4jq-g83v",
  "modified" : "2026-09-04T15:36:13Z",
  "published" : "2026-09-04T15:36:13Z",
  "aliases" : [ "CVE-2026-85621" ],
  "details" : "LobeChat (LobeHub) 2.2.1 does not properly verify inbound chat-platform webhook signatures in the QQ and Feishu adapters. The webhook route (/api/agent/webhooks/:platform) is unauthenticated by design and delegates verification to each adapter; the QQ adapter performs no Ed25519 signature verification on dispatched message events, and the Feishu adapter only performs an optional static-token comparison that is skipped when no token is configured (the default) and is not a body signature. An unauthenticated attacker who knows the public webhook URL can POST forged inbound messages with an attacker-chosen sender identity and arbitrary text, causing the bot owner's agent to process attacker-controlled input and treat the attacker as a trusted platform sender.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-85621"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lobehub/lobehub/issues/16538"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lobehub/lobehub"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-feishu/src/adapter.ts"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/lobehub/lobehub/blob/v2.2.15/packages/chat-adapter-qq/src/adapter.ts"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/lobechat-2.2.1-webhook-signature-verification-bypass-qq-feishu"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-345" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-04T15:17:42Z"
  }
}