CVE-2026-116078

HTTP/2 request bodies made of 1-byte DATA frames amplify memory use in Bandit

State
Published
Severity
8.7 High
Published
Oct 28, 2026
Updated
Oct 28, 2026
Reserved
Oct 25, 2026

Read the record on cve.org

Description

Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a request body sent as many 1-byte DATA frames.

do_read_data/5 in lib/bandit/http2/stream.ex keeps every DATA frame payload as its own list element until the read returns. The :length option of read_body/2 counts body bytes, not frames, so a body of 1-byte frames costs a list cell and a binary term per byte. Interleaving the frames across up to 500 concurrent streams per connection keeps each stream consuming its frames as they arrive; in the reporter's test, 100 streams held 25 to 40 MiB of stream process memory for 5 MB sent. Only routes whose Plug reads the request body are affected, which includes any route behind Plug.Parsers.

This issue affects bandit: from 0.3.1 before 1.14.1.

Scores

CVSSScoreVectorSource
4.08.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NEEF

Weaknesses

  • CWE-770 Allocation of Resources Without Limits or Throttling

Affected Products

ProductVersions
banditmtrudel
  • 0.3.1 to before 1.14.1Affected
banditmtrudel
  • c8dc1e97050cf359f61ed6cdd110f3cdaf1d6f5f to before 327bb02ff84171237e1aeff787930debd16155eeAffected

References

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