UBUNTU-CVE-2026-9675

Advisory lineage Upstream: 1 Downstream: 0
Upstream
CVE-2026-9675
Published: 17 Jun 2026, 17:17
Last modified:24 Jun 2026, 11:00

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
3.1 (osv_ubuntu)
EPSS Score
No data
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

17 Jun 2026, 17:17
Published
Vulnerability first disclosed
24 Jun 2026, 11:00
Last Modified
Vulnerability information updated

Description

Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service. Affected applications are those using the undici WebSocket client (new WebSocket(...)) that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint. This is a regression specific to undici 8.1.0. The 6.25.0 line shipped the equivalent cumulative check from the start and is unaffected. The 7.x line never had the maxPayloadSize feature and is also unaffected. Patches: Upgrade to undici >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Systems

  • ubuntu•node-undici

    all | all | all

References (3)