Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body…

Why it is Yellow

• CVSS 8.7 high
• Remotely exploitable without logging in

References

• https://cna.erlef.org/cves/CVE-2026-115269.html
• https://github.com/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a
• https://github.com/mtrudel/bandit/commit/fff06efe3be962b484bd4d3eb339372fda5a231f
• https://github.com/mtrudel/bandit/security/advisories/GHSA-p2qv-vx88-385x
• https://osv.dev/vulnerability/EEF-CVE-2026-115269

Original 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.