CVE-2026-63095

Dendrite 0.13.8 Improper Authorization via POST account/3pid/delete Endpoint

MEDIUM
6.5
CVSS Score
Published: July 17, 2026 at 03:27 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
2 products affected across 2 vendorsDendriteDendrite

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 0.13.8
0 ≤ v ≤ 0.13.80

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-639

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