CVE-2026-111101

HTTP/1.1 chunked request bodies made of 1-byte chunks amplify memory use in Bandit

HIGH
8.7
CVSS Score
Published: October 26, 2026 at 01:31 PM UTC
Updated: October 26, 2026 at 04:59 PM UTC
1 product affected across 1 vendorBandit

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Severity
HIGH8.7
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

Description

Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory and CPU via a request body made of many 1-byte chunks. The chunked reader in lib/bandit/http1/socket.ex keeps every chunk as its own list cell and binary term until IO.iodata_to_binary/1 joins them, and nothing limits the number of chunks. The :length option of read_body/2 counts only data bytes, so tiny chunks cost far more memory than their payload: 48 MB of 1-byte chunks grew one handler process to about 500 MB and took about 6 s of CPU. The route does not need to read the body, because on keep-alive connections ensure_completed/1 drains unread bodies through the same reader. This issue affects bandit: from 0.1.0 before 1.14.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.1.07201270c34b90f6c9e15c0386c2bb802c0c72ab4

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHEEF
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-770

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