TI-2026-66116 Aliases CVE-2026-104480 GHSA-3q99-x36r-rchh

Improper MLS Welcome roster validation in Discord libdave allows unauthorized group membership

MEDIUM 43CWE-390Published 2026-10-02 · Updated 2026-10-02

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: Present
Impact type: Security bypass
Confidentiality · integrity · availability: High · High · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-863.

Summary

Discord libdave before 1.2.0 did not reject an MLS Welcome message when the resulting group roster contained an unrecognized participant. An attacker in control of the DAVE signaling path (the voice gateway, or an equivalent position able to add, alter, or withhold signaling messages to a client) could cause affected clients to accept an unauthorized member into the end-to-end encrypted media session, compromising the confidentiality and integrity of audio and video.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00397 34th percentileScored 2026-11-07

Fix Fixed libdave (Discord): 1.2.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

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

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Discord	libdave	1.1.0 to before 1.2.0	1.2.0	Patch available	CNA

libdave VendorDiscord Affected 1.1.0 to before 1.2.0 Fixed in 1.2.0 Patch available CNA

Remediation

Fix · CNA libdave (Discord) Fixed in 1.2.0

Timeline

2026-10-02 Threatist record created from CVE-2026-104480
2026-10-03 Alias added: GHSA-3q99-x36r-rchh

References

Patch 1

[cpp] restore strict validation of MLS welcome state

Other 3

TI-2024-15743 An issue in Discord for macOS version 0.0.291 and before, allows remote attackers to… CVSS 3.1CRITICAL 9.8
TI-2025-04040 Discord WINSTA.dll uncontrolled search path CVSS 4.0HIGH 7.3
TI-2021-10178 Remote file overwrite on discord-recon can result in DoS and Remote Code Execution CVSS 3.1CRITICAL 9.8
TI-2021-10179 Path Traversal at Discord-Recon .recon Command Path CVSS 3.1HIGH 7.5
TI-2026-00559 Uncontrolled search path in Discord Client CVSS 3.0HIGH 7.3
TI-2026-19615 Discord through 2026-01-16 allows gathering information about whether a user's client… CVSS 3.1MEDIUM 4.3

Sources

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