Impact: The undici WebSocket client enforces maxPayloadSize on the cumulative byte count of fragments in a message but does not enforce a limit on the number of fragments. A malicious WebSocket server can stream many small or empty continuation frames that each pass per-frame and cumulative-size validation, collectively 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(...)) or the WebSocketStream API that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint.
All releases starting at undici 6.17.0 are affected.
Patches: Upgrade to undici >= 6.26.0, >= 7.28.0, or >= 8.5.0. Workarounds: No workaround is available. The fix must be applied through an upgrade.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade v8-13.6-develUpgrade v8-12.4-develUpgrade npmUpgrade nodejs-develUpgrade nodejs-packaging-bundlerUpgrade nodejs-nodemonUpgrade nodejs-packagingUpgrade nodejs-libsUpgrade nodejsUpgrade nodejs-docsUpgrade nodejs-full-i18n | Jul 7, 2026 | Jul 6, 2026 |
| Amazon_linux_2023 | — | Upgrade nodejs22-debuginfoUpgrade v8-13.6-develUpgrade nodejs24-docsUpgrade nodejs24-npmUpgrade nodejs24-develUpgrade nodejs22-debugsourceUpgrade nodejs24-libsUpgrade nodejs22-develUpgrade nodejs22-libs-debuginfoUpgrade nodejs22-docsUpgrade nodejs24-debugsourceUpgrade nodejs22-npmUpgrade nodejs24-debuginfoUpgrade nodejs24-full-i18nUpgrade nodejs24Upgrade nodejs22Upgrade nodejs22-libsUpgrade v8-12.4-develUpgrade nodejs24-libs-debuginfoUpgrade nodejs22-full-i18n | Jul 8, 2026 | Jun 17, 2026 |
| Atlassian Jira | — | Upgrade to the latest version of Atlassian JIRA | Aug 19, 2026 | Aug 18, 2026 |
| Redhat_linux | — | Upgrade v8-12.4-develUpgrade nodejs24-docsUpgrade npmUpgrade nodejs-npmUpgrade nodejs24-npmUpgrade nodejs22-debuginfoUpgrade nodejs24-debuginfoUpgrade v8-13.6-develUpgrade nodejs24-libs-debuginfoUpgrade nodejs24-full-i18nUpgrade nodejs-nodemonUpgrade nodejs-debuginfoUpgrade nodejs24-develUpgrade nodejs-libs-debuginfoUpgrade nodejs-packagingUpgrade nodejs24-libsUpgrade nodejs-docsUpgrade nodejs-packaging-bundlerUpgrade nodejsUpgrade nodejs24-debugsourceUpgrade nodejs-debugsourceUpgrade nodejs24Upgrade nodejs22-debugsourceUpgrade nodejs-full-i18nUpgrade nodejs-develUpgrade nodejs-libs | Jul 7, 2026 | Jun 17, 2026 |
| Rocky_linux | — | Upgrade v8-12.4-develUpgrade nodejs24-libs-debuginfoUpgrade nodejs24-debugsourceUpgrade nodejs-full-i18nUpgrade nodejs-debuginfoUpgrade nodejs24-full-i18nUpgrade nodejs-debugsourceUpgrade nodejsUpgrade nodejs24-libsUpgrade nodejs-npmUpgrade nodejs-libsUpgrade npmUpgrade nodejs22-debuginfoUpgrade nodejs24-debuginfoUpgrade v8-13.6-develUpgrade nodejs-develUpgrade nodejs22-debugsourceUpgrade nodejs-libs-debuginfoUpgrade nodejs24Upgrade nodejs24-devel | Jul 10, 2026 | Jul 7, 2026 |
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