CVE-2026-63095

Dendrite through 0.13.8 contains an improper authorization vulnerability in the Matrix Client-Server API that allows any authenticated local user to delete third-party identifier bindings belonging to other users by submitting an arbitrary address and medium to the account deletion endpoint without ownership verification. Attackers can exploit the unverified Forget3PID handler to remove a victim's email or MSISDN binding and subsequently rebind the address through an identity server to hijack the victim's password reset flow.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/geo-chen/oss/blob/main/dendrite.md#finding-1-idor-in-post-account3piddelete-allows-any-authenticated-user-to-remove-any-other-users-third-party-identifier
https://www.vulncheck.com/advisories/dendrite-improper-authorization-via-post-account-3pid-delete-endpoint

Configurations

No configuration.

History

17 Jul 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-17 16:17

Updated : 2026-07-17 18:04

NVD link : CVE-2026-63095

Mitre link : CVE-2026-63095

CVE.ORG link : CVE-2026-63095

JSON object : View

Products Affected

No product.

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

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