CVE-2026-108525 HTTP/2 inbound flow control is not enforced, letting a client queue unbounded DATA in stream processes in Bandit
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-108525?
CVE-2026-108525 is a high-severity vulnerability in mtrudel bandit, published on 26 Oct 2026.
Official description
Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via DATA frames sent past the advertised receive window. The attacker requests a response larger than the 65,535-byte initial window and withholds WINDOW_UPDATE, so the stream process blocks while sending and stops reading, then floods small DATA frames on that stream. Every frame is queued in the stream's mailbox until the BEAM node runs out of memory.
Bandit.HTTP2.Connection.handle_frame/3 in lib/bandit/http2/connection.ex forwards each DATA frame to the stream process without consulting the receive window, and Bandit.HTTP2.FlowControl.compute_recv_window/2 replenishes the window as data arrives rather than as it is consumed, and never answers a violation with FLOW_CONTROL_ERROR.
This issue affects bandit: from 0.3.1 before 1.14.0.
Weakness: CWE-770
Which versions are affected by CVE-2026-108525?
1 open source package ship an affected version, including bandit.
| Package | Affected | Fixed in |
|---|---|---|
bandit Hex | From 0.3.1 | 1.14.0 |
How do I fix CVE-2026-108525?
Upgrade bandit to 1.14.0 or later.
Is CVE-2026-108525 being exploited?
There is no known exploitation of CVE-2026-108525 in the wild and no public exploit code.
Sources
Also known as EEF-CVE-2026-108525, GHSA-c3g7-2pg5-qvwh, UBUNTU-CVE-2026-108525.