{"id":"CVE-2026-116078","title":"HTTP/2 request bodies made of 1-byte DATA frames amplify memory use in Bandit","summary":"Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a request body sent as many 1-byte DATA frames.…","severity":"high","cvss":8.7,"cvssVector":"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","cvssSource":"cna","cwe":["CWE-770"],"vendor":"mtrudel","product":"bandit","affected":["bandit >= 0.3.1 < 1.14.1","mtrudel/bandit >= c8dc1e97050cf359f61ed6cdd110f3cdaf1d6f5f < 327bb02ff84171237e1aeff787930debd16155ee"],"published":"2026-10-28","updated":"2026-10-28","sourceUpdated":"2026-10-28T13:26:25.372Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-116078","references":[{"url":"https://github.com/mtrudel/bandit/security/advisories/GHSA-pxjf-g536-7r93","label":"HTTP/2 request bodies made of 1-byte DATA frames amplify memory use in Bandit"},{"url":"https://cna.erlef.org/cves/CVE-2026-116078.html","label":"EEF CNA record for CVE-2026-116078"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-116078","label":"OSV record EEF-CVE-2026-116078"},{"url":"https://github.com/mtrudel/bandit/commit/c8dc1e97050cf359f61ed6cdd110f3cdaf1d6f5f","label":"Introducing commit c8dc1e9 in mtrudel/bandit"},{"url":"https://github.com/mtrudel/bandit/commit/327bb02ff84171237e1aeff787930debd16155ee","label":"Fix commit 327bb02 in mtrudel/bandit"}],"tags":["cve.org"],"ingestedAt":"2026-10-28T14:12:18.562Z","slug":"CVE-2026-116078","body":"## Overview\n\nAllocation of Resources Without Limits or Throttling vulnerability in the HTTP/2 request body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory via a request body sent as many 1-byte DATA frames.\n\ndo_read_data/5 in lib/bandit/http2/stream.ex keeps every DATA frame payload as its own list element until the read returns. The :length option of read_body/2 counts body bytes, not frames, so a body of 1-byte frames costs a list cell and a binary term per byte. Interleaving the frames across up to 500 concurrent streams per connection keeps each stream consuming its frames as they arrive; in the reporter's test, 100 streams held 25 to 40 MiB of stream process memory for 5 MB sent. Only routes whose Plug reads the request body are affected, which includes any route behind Plug.Parsers.\n\nThis issue affects bandit: from 0.3.1 before 1.14.1.\n\n## Affected\n\n- `bandit >= 0.3.1 < 1.14.1`\n- `mtrudel/bandit >= c8dc1e97050cf359f61ed6cdd110f3cdaf1d6f5f < 327bb02ff84171237e1aeff787930debd16155ee`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n### Workarounds\n\nFrom 0.7.0, disable HTTP/2 with http_2_options: [enabled: false], so that the vulnerable body reader never runs.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":47.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}