6.9

CVE-2026-42788

HTTP/2 frame size limit checked after body is buffered in bandit

Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated memory exhaustion via oversized HTTP/2 frames.

'Elixir.Bandit.HTTP2.Frame':deserialize/2 in lib/bandit/http2/frame.ex checks the SETTINGS_MAX_FRAME_SIZE limit only after pattern-matching payload::binary-size(length), which requires the entire frame body to be present in memory before either the accept or reject clause can fire. A peer that announces a frame length up to the 24-bit maximum (~16 MiB) causes the server to buffer that entire body before the size guard is evaluated, regardless of the max_frame_size negotiated during the HTTP/2 handshake (default 16 KiB per RFC 9113).

An unauthenticated attacker holding many concurrent connections can force the server to buffer far more memory than the negotiated frame size limit should permit, leading to memory pressure and potential denial of service.

This issue affects bandit: from 0.3.6 before 1.11.0.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
Herstellermtrudel
≫
Produkt bandit
Default Statusunaffected
Version 0.3.6
Version < 1.11.0
Status affected
Herstellermtrudel
≫
Produkt bandit
Default Statusunaffected
Version f00dd69a5b2a4863be585907acd853c4ffd41399
Version < 1e8e55966da9129016b73d32f0e1df4630e3b463
Status affected
VulnDex Vulnerability Enrichment
Diese Information steht angemeldeten Benutzern zur Verfügung. Login Login
Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.51% 0.393
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
6b3ad84c-e1a6-4bf7-a703-f496b71e49db 6.9 0 0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE-770 Allocation of Resources Without Limits or Throttling

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

https://github.com/mtrudel/bandit/security/advisories/GHSA-q6v9-r226-v65f
https://cna.erlef.org/cves/CVE-2026-42788.html
https://osv.dev/vulnerability/EEF-CVE-2026-42788
https://github.com/mtrudel/bandit/commit/1e8e55966da9129016b73d32f0e1df4630e3b463