PT-2026-60788 · Matrix.Org · Dendrite

George Chen · CVE-2026-63095 · Published 2026-07-17 · Updated 2026-07-17

Mitre

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

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.

Exploit

Fix

IDOR

Weakness Enumeration

CWE-639

Related Identifiers

CVE-2026-63095

Affected Products

Dendrite

References · 3

• 🔥 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 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-63095 · Security Note
• https://vulncheck.com/advisories/dendrite-improper-authorization-via-post-account-3pid-delete-endpoint · Note