CVE-2026-104480

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

Published Oct 2, 2026 CVSS 4.0 · 9.4 Critical EPSS < 1% KEV · Not listed
Description
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.

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': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Discord
Discord libdave
Vendors & Products Discord
Discord libdave
Type Values Removed Values Added
Description 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.
Title Improper MLS Welcome roster validation in Discord libdave allows unauthorized group membership
Weaknesses CWE-390
CWE-863
References
Metrics cvssV4_0

{'score': 9.4, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Bugcrowd
Published
Updated
Oct 2, 2026, 6:18 PM
Reserved
Oct 2, 2026, 12:57 AM
Status
Awaiting Analysis
Published
Oct 2, 2026, 2:17 AM
Modified
Oct 2, 2026, 7:16 PM