CVE-2026-84947: low-severity vulnerability in undici
undici vulnerable to response truncation via oversized chunked responses in the dump interceptor
Published
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8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 3.7epss 0.2%
undici's dump interceptor reads and discards a response body up to a configurable maximum size. When a response declares a Content-Length that exceeds the maximum, the interceptor aborts cleanly, but when a response has no Content-Length and is chunked, the interceptor instead signals completion early once the accumulated size reaches the maximum, without pausing or aborting the request. Because the underlying parser keeps delivering body bytes, a second completion signal fires and trips an internal assertion, which aborts the request and tears down the connection. The application is left observing a misleading successful status with an empty or truncated body while the connection has actually been disconnected. This affects undici versions from 7.1.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
undici · undiciRelated CVEs — undici
In the same product, most dangerous first.
CVE-2026-1526HIGHundici is vulnerable to Unbounded Memory Consumption in undici WebSocket permessage-deflate DecompressionEPSS 1.2%CVE-2026-2229HIGHundici is vulnerable to Unhandled Exception in undici WebSocket Client Due to Invalid server_max_window_bits ValidationEPSS 0.9%CVE-2026-12151HIGHundici WebSocket client vulnerable to denial of service via fragment count bypassEPSS 0.8%CVE-2026-2581MEDIUMundici is vulnerable to Unbounded Memory Consumption in in Undici's DeduplicationHandler via Response Buffering leads to DoSEPSS 0.6%CVE-2026-13697HIGHundici vulnerable to cross-user information disclosure and parse-time crash via degenerate private cache directivesEPSS 0.6%CVE-2026-1525MEDIUMundici is vulnerable to Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')EPSS 0.5%