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TI-2026-45045 Aliases CVE-2026-63095GHSA-35h8-2q42-v6f5

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

Priority MEDIUM 64CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00296 22nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
matrix-orgdendriteup to 0.13.8—No fix listedCNA
  • dendrite Vendormatrix-org Affected up to 0.13.8 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63095
  2. 2026-10-03 Alias added: GHSA-35h8-2q42-v6f5

References

Exploit 1

  • TI-2023-20035 Sydent does not verify email server certificates CVSS 3.1CRITICAL 9.3
  • TI-2026-45046 Dendrite 0.13.8 SSRF via Unauthenticated Legacy Media Download Endpoint CVSS 4.0MEDIUM 6.9
  • TI-2026-45047 Dendrite 0.13.8 syncapi /context Endpoint Post-Leave State Exposure CVSS 4.0MEDIUM 5.3
  • TI-2023-15617 Synapse Outgoing federation to specific hosts can be disabled by sending malicious invites CVSS 3.1MEDIUM 5.0
  • TI-2023-20039 matrix-appservice-irc IRC command injection via admin commands containing newlines CVSS 3.1CRITICAL 9.8
  • TI-2021-13807 Matrix libolm before 3.2.3 allows a malicious Matrix homeserver to crash a client (while… CVSS 3.1CRITICAL 9.8
See all 115 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences