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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| mtrudel | bandit | 1.4.0 – < 1.14.0 | 1.14.0 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | bandit | No fix yet | — |
| Ubuntu 26.04 LTS | bandit | No fix yet | — |
| Ubuntu 24.04 LTS | bandit | No fix yet | — |
| Ubuntu 22.04 LTS | bandit | No fix yet | — |
| Ubuntu 20.04 LTS | bandit | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | bandit | No fix yet | — |
| Ubuntu 16.04 LTS | bandit | No fix yet | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Hex | bandit | >= 1.4.0, < 1.14.0 | 1.14.0 | EEF-CVE-2026-115269 |
References
- HTTP/2 WINDOW_UPDATE and SETTINGS frames reset the request body read timeout in Bandit vendor-advisory related
- EEF CNA record for CVE-2026-115269 related
- OSV record EEF-CVE-2026-115269 related
- Introducing commit fff06ef in mtrudel/bandit related
- Fix commit 220b9df in mtrudel/bandit patch