CVE-2026-108529SETTINGS and stream-0 WINDOW_UPDATE frames trigger quadratic work over blocked streams in Bandit
Updated under an hour ago ()
Does this affect you?
It affects mtrudel bandit. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.60%, higher than 49% of scored CVEs.
Inefficient Algorithmic Complexity vulnerability in the HTTP/2 implementation of mtrudel bandit allows an unauthenticated remote attacker to exhaust server CPU via small SETTINGS or connection-level WINDOW_UPDATE frames. The attacker opens thousands of streams whose responses block on the connection send window, then sends cheap frames that each make the server walk the whole queue of blocked sends. In the reporter's run, with 3,000 blocked streams a single 9-byte SETTINGS frame took 133 ms to process. do_pending_sends/2 in lib/bandit/http2/connection.ex retries every queued send and, before each retry, removes that entry from the queue with List.delete/2, so one frame costs O(n²) list operations for n blocked streams. max_concurrent_streams defaults to :infinity, so the attacker chooses n. This issue affects bandit: from 0.3.4 before 1.14.0.
- CVSS
- 8.7 HIGH (v4.0, CNA)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
- Weakness (CWE)
- CWE-407
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.60% (percentile 49)
- Assigned by
- EEF
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 26, 2026
- First seen by InfoSec Signals
- Oct 26, 2026
The CVE record on cve.org NVD's entry
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