CVE-2026-111101 json
HTTP/1.1 chunked request bodies made of 1-byte chunks amplify memory use in Bandit
published 2026-10-26 13 d ago modified 2026-10-26 13 d ago also EEF-CVE-2026-111101 , GHSA-jwh3-j29h-qfmw , EUVD-2026-109824
- cvss
- 8.7
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 49%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- hex bandit 1.14.0
- mtrudel bandit 1.14.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 13 d ago
Exploit prediction
0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | 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 |
| CNA | 4.0 | 8.7 | 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 |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| hex | bandit | >=0.1.0, <1.14.0 |
1.14.0 |
Affected products
- mtrudel bandit
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
github.com
/mtrudel/bandit/commit/7201270c34b90f6c9e15c0386c2bb802c0c72ab4
related, web
-
github.com
/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a
patch
-
github.com
/mtrudel/bandit/security/advisories/GHSA-jwh3-j29h-qfmw
vendor-advisory, related, advisory
-
cna.erlef.org
/cves/CVE-2026-111101.html
related, web
-
osv.dev
/vulnerability/EEF-CVE-2026-111101
related
-
hex.pm
/packages/bandit
package
Sources
- CVE List CVE-2026-111101
- NVD CVE-2026-111101
- OSV EEF-CVE-2026-111101
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.