CVE-2026-97200highCWE-409CWE-770

CVE-2026-97200: high-severity vulnerability in benoitc hackney

Unbounded response body buffering and decompression in hackney

Published

Follow this CVE+ Monitor hackney+ Monitor hackney

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.2epss 0.6%
Allocation of Resources Without Limits or Throttling vulnerability in hackney_conn in benoitc hackney allows a malicious HTTP server to exhaust client memory via an oversized or highly compressed response body. hackney:request/5 and hackney:body/1 return the whole response body, and nothing bounds how much the connection process buffers. Any server the client requests can trigger it. hackney_conn:read_full_body/2 and the HTTP/2 and HTTP/3 accumulators append every chunk until the body ends. With {auto_decompress, true} the buffered body is then inflated in one step with zlib:gunzip/1 or zlib:inflate/2, which return the whole output at once. This issue affects hackney: from 2.0.0-beta.1 before 4.9.0.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
benoitc · hackney
Related CVEs — benoitc hackney

In the same product, most dangerous first.

CVE-2026-47073HIGHUnbounded memory consumption in WebSocket client in hackneyEPSS 0.9%CVE-2026-47067HIGHAtom table exhaustion via unrecognized URL schemes in hackneyEPSS 0.8%CVE-2026-47071HIGHSOCKS5 TLS upgrade ignores caller timeout in hackneyEPSS 0.8%CVE-2026-47066HIGHInfinite loop in Alt-Svc header parser in hackneyEPSS 0.8%CVE-2026-47077HIGHUnbounded body accumulation in HTTP/3 response loop in hackneyEPSS 0.7%CVE-2026-47072MEDIUMCRLF injection in WebSocket upgrade request in hackneyEPSS 0.5%