CVE-2026-114216 json
Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit
published 2026-10-26 13 d ago modified 2026-10-26 13 d ago also EEF-CVE-2026-114216 , GHSA-w5wc-g2hc-g7m2 , EUVD-2026-109820
- cvss
- 6.3
- 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
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to smuggle a second request past a front-end proxy via a chunk extension that contains a bare LF.
The chunked reader in lib/bandit/http1/socket.ex takes the chunk-size line to be everything up to the first CRLF and discards everything after ; without checking it against the RFC 9112 chunk-ext grammar, so bare LF, bare CR and other control bytes pass. A proxy that ends the size line at a bare LF reads 2;\nxx\r\n40\r\n... as one request whose second chunk holds a GET /admin, while Bandit ends the body early and dispatches GET /admin as a separate pipelined request. Deployments without such a proxy in front of Bandit are not affected.
This issue affects bandit: from 1.12.4 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 | 6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N |
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/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 | >=1.12.4, <1.14.0 |
1.14.0 |
Affected products
- mtrudel bandit
Classification
- Weakness
-
- CWE-444 Inconsistent Interpretation of HTTP Requests
References
-
github.com
/mtrudel/bandit/commit/c31e9e3c76dcbfc239a96eabed5341ced7885ae5
related, web
-
github.com
/mtrudel/bandit/commit/220b9dfd27f9a21305be2afc75cbe585ddc24e7a
patch
-
github.com
/mtrudel/bandit/security/advisories/GHSA-w5wc-g2hc-g7m2
vendor-advisory, related, advisory
-
cna.erlef.org
/cves/CVE-2026-114216.html
related, web
-
osv.dev
/vulnerability/EEF-CVE-2026-114216
related
-
hex.pm
/packages/bandit
package
Sources
- CVE List CVE-2026-114216
- NVD CVE-2026-114216
- OSV EEF-CVE-2026-114216
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