undici vulnerable to Denial of Service via unbounded memory in the EventSource parser

CAO 7.5CVE-2026-109924 · GHSA-4qv8-2p9j-2685 · Công bố 15/10/2026 · cập nhật 19/10/2026

Tóm tắt nhanh

CVE-2026-109924 là lỗ hổng mức CAO (CVSS 7.5) ảnh hưởng undici (nodejs), undici.
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.32%, cao hơn 25.1% các lỗ hổng khác.
Cách xử lý: cập nhật lên 6.29.1, 7.30.1, 8.12.2 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
undici nodejs	`≥ 6.5.0, < 6.29.1≥ 7.0.0, < 7.30.1≥ 8.0.0, < 8.12.2`	`6.29.17.30.18.12.2`
undici npm	`≥ 6.5.0, < 6.29.1≥ 7.0.0, < 7.30.1≥ 8.0.0, < 8.12.2`	`6.29.17.30.18.12.2`

Mô tả

Impact

undici's EventSource client can be driven to exhaust process memory by a malicious or compromised Server-Sent Events peer. By sending millions of tiny completed data: fields with no blank event separator, or a single unfinished line split across many chunks, the parser retains a growing amount of per-field and per-chunk state. The byte-based maxEventSize and maxResponseSize limits do not bound that retained state, and maxResponseSize is enforced on the compressed body before decompression, so a small compressed response can expand into enough retained memory to terminate the process. The application only needs to maintain an EventSource connection to an untrusted peer, which controls only the response. Availability is the only impact.

Patches

Upgrade to 6.29.1, 7.30.1, or 8.12.2, which bound the retained EventSource parser state (the number of data fields and buffered chunks, the unfinished-line length, and per-field byte totals) independently of the byte limits.

Workarounds

None.

Mô tả của NVD

undici is an HTTP client library for Node.js. In versions 6.5.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its EventSource client can be driven to exhaust process memory by a malicious or compromised Server-Sent Events peer. By sending millions of tiny completed data fields with no blank event separator, or a single unfinished line split across many chunks, the parser retains a growing amount of per-field and per-chunk state that the byte-based maxEventSize and maxResponseSize limits do not bound, and because maxResponseSize is enforced on the compressed body before decompression, a small compressed response can expand into enough retained memory to terminate the process. An application only needs to maintain an EventSource connection to an untrusted peer, which controls only the response, and availability is the only impact. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which bound the retained parser state independently of the byte limits, and users should upgrade to one of those versions or later. There is no workaround.