CVE-2026-63095

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

Published Jul 17, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Matrix
Matrix dendrite
CPEs cpe:2.3:a:matrix:dendrite:*:*:*:*:*:*:*:*
Vendors & Products Matrix
Matrix dendrite
Type Values Removed Values Added
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.
Title Dendrite 0.13.8 Improper Authorization via POST account/3pid/delete Endpoint
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Jul 28, 2026, 1:49 AM
Reserved
Jul 15, 2026, 3:45 PM
Status
Deferred
Published
Jul 17, 2026, 4:17 PM
Modified
Oct 24, 2026, 8:10 PM