PT-2026-43073 · Benoitc · Hackney

Benoit Chesneau + 2 · Published 2026-05-25 · Updated 2026-05-25 · CVE-2026-47077

Mitre

CVSS v4.0

8.2

High

Base vector

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackney h3:await response loop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk, housekeeping message, or settings frame — it is not a wall-clock deadline. A malicious HTTP/3 server that emits one small chunk every Timeout - 1 ms with Fin = false and never sends a final frame keeps the loop alive indefinitely while the accumulation buffer grows linearly without bound, eventually exhausting the BEAM process heap and causing an out-of-memory condition.

This issue affects hackney: from 2.0.0 before 4.0.1.

Fix

Resource Exhaustion

Weakness Enumeration

CWE-400

Related Identifiers

CVE-2026-47077

Affected Products

Hackney

References · 4

• https://github.com/benoitc/hackney/security/advisories/GHSA-jq4m-q6p2-8gwc · Vendor Advisory
• https://github.com/benoitc/hackney/commit/3d25f9fea26c90609de9d64366fedfe5065413bc · Patch
• https://cna.erlef.org/cves/CVE-2026-47077.html · Note
• https://osv.dev/vulnerability/EEF-CVE-2026-47077 · Note