Vulnerability · Published Oct 26, 2026 · Assigned by EEF
CVE-2026-115269HTTP/2 WINDOW_UPDATE and SETTINGS frames reset the request body read timeout in Bandit
High 8.7
In plain English
A high-severity infinite loop in bandit from mtrudel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% 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 hold stream processes open indefinitely via WINDOW_UPDATE or empty SETTINGS frames sent while a Plug reads the request body. Bandit.HTTP2.Stream.do_read_data/4 in lib/bandit/http2/stream.ex waits for each frame with a fresh read_timeout. A stream WINDOW_UPDATE, or the zero-delta window update that every empty SETTINGS frame delivers to all streams, ends the wait without delivering any body data, and the loop starts a new full countdown. A client that sends one of these 9-byte frames before each countdown expires keeps read_body blocked, together with the stream process and whatever the application holds while reading, for as long as it likes. This issue affects bandit: from 1.4.0 before 1.14.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | bandit | no fix listed | UBUNTU-CVE-2026-115269 |
| Ubuntu:24.04:LTS | bandit | no fix listed | UBUNTU-CVE-2026-115269 |
| Ubuntu:26.04:LTS | bandit | no fix listed | UBUNTU-CVE-2026-115269 |
| Ubuntu:26.10 | bandit | no fix listed | UBUNTU-CVE-2026-115269 |
Affected products (as reported)
Weakness: CWE-835, 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