CVE-2026-9675
undici WebSocket client vulnerable to denial of service via cumulative fragment bypass
描述
## 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.
如何修補 CVE-2026-9675
要修補 CVE-2026-9675,請將受影響套件升級到下列已修補版本。
- —升級至 8.5.0 或更新版本
CVE-2026-9675 正在被利用嗎?
目前沒有被利用訊號。CVE-2026-9675 既不在 CISA KEV 也沒有最新的 EPSS 分數。
受影響套件(1)
- >= 8.0.0, < 8.5.0
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |