Vulnerability · Published Oct 28, 2026 · Assigned by EEF
CVE-2026-116078HTTP/2 request bodies made of 1-byte DATA frames amplify memory use in Bandit
High 8.7
In plain English
A high-severity resource allocation without limits in bandit from mtrudel. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | bandit | no fix listed | UBUNTU-CVE-2026-116078 |
| Ubuntu:24.04:LTS | bandit | no fix listed | UBUNTU-CVE-2026-116078 |
| Ubuntu:26.04:LTS | bandit | no fix listed | UBUNTU-CVE-2026-116078 |
| Ubuntu:26.10 | bandit | no fix listed | UBUNTU-CVE-2026-116078 |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N