Discord libdave: Improper MLS Welcome roster validation allows unauthorized members
Summary
Discord libdave, the C++ and JavaScript library implementing the DAVE end-to-end encryption protocol for voice and video, accepts an MLS Welcome message even when the resulting group roster contains an unrecognized participant. An attacker who controls the DAVE signaling path, such as the voice gateway or an equivalent position that can add, alter or withhold signaling messages, can cause affected clients to admit an unauthorized member into an encrypted media session. This can compromise the confidentiality and integrity of audio and video. The attacker needs a privileged position in the signaling path, so exploitation by typical network attackers is considered difficult.
Affected
- Discord libdave before 1.2.0
- Per CNA: 1.1.0 to before 1.2.0, and commits from 7b15f1fc16f159da0478aa6be909e38f1e957833 up to 9686fbaea864aa19f0675e486672b6a77811b6a1
- Whether releases before 1.1.0 are affected: Unknown.
- Discord client builds that embed affected libdave versions: Unknown.
Fixed in
- libdave 1.2.0 (commit 9686fbaea864aa19f0675e486672b6a77811b6a1)
Workaround
- No vendor workaround known.
- For applications embedding libdave: add a regression test that rejects a Welcome message referencing an unknown participant until the update is applied.
Exploitation
- No known exploitation in the wild.
- CISA SSVC: Exploitation none, automatable no, technical impact total.
- No public proof of concept reported.
Our recommendation
- Update libdave to 1.2.0 or later in every application you own or manage that embeds it.
- For Discord itself, keep the client on automatic updates and confirm it is current.
- Monitor vendor releases for further details or a Discord advisory.
- Priority for SMEs: medium, given the high score but difficult attacker position and no known exploitation.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Discord libdave GitHub repository github.com
- libdave v1.2.0 release github.com
- Fix commit 9686fbaea864aa19f0675e486672b6a77811b6a1 github.com
- DAVE protocol whitepaper daveprotocol.com
- OSV entry CVE-2026-104480 osv.dev
- Strix CVE-2026-104480 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 00:15.
Original description (NVD)
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.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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