bandit: Allocation of Resources Without Limits or Throttling
CVE-2026-111101 is a high-severity allocation of resources without limits or throttling vulnerability in bandit from Mtrudel, with a CVSS 4.0 base score of 8.7 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 1.14.0, 220b9dfd27f9a21305be2afc75cbe585ddc24e7a as the first without the flaw, so updating bandit to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.6% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update bandit to 1.14.0 or 220b9dfd27f9a21305be2afc75cbe585ddc24e7a, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mtrudel | bandit | 0.1.0 up to, but not including, 1.14.0; 7201270c34b90f6c9e15c0386c2bb802c0c72ab4 up to, but not including, 220b9dfd27f9a21305be2afc75cbe585ddc24e7a | 1.14.0, 220b9dfd27f9a21305be2afc75cbe585ddc24e7a |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- NoneNo loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- NoneNo loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: 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/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. Scored by CNA.
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: 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 intended restrictions on the size or number of resources that can be allocated.
How developers prevent this class of flaw
- Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
- Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Allocation of Resources Without Limits or Throttling vulnerabilities (CWE-770)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
References
Patches and release notes
Other vulnerabilities in bandit
- 8.7 High severity
- 8.7 High severity
- 8.7 High severity
- 8.7 High severity
- 8.2 High severity
- 8.7 High severity
Recent Allocation of Resources Without Limits or Throttling vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 8.7 High severity
- 7.5 High severity
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