CVE-2026-114216 Chunk extensions accept bare LF and CR, enabling request smuggling in Bandit
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-114216?
CVE-2026-114216 is a medium-severity vulnerability in mtrudel bandit, published on 26 Oct 2026.
Official description
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.
Weakness: CWE-444
Which versions are affected by CVE-2026-114216?
1 open source package ship an affected version, including bandit.
| Package | Affected | Fixed in |
|---|---|---|
bandit Hex | From 1.12.4 | 1.14.0 |
How do I fix CVE-2026-114216?
Upgrade bandit to 1.14.0 or later.
Is CVE-2026-114216 being exploited?
There is no known exploitation of CVE-2026-114216 in the wild and no public exploit code.
Sources
Also known as EEF-CVE-2026-114216, GHSA-w5wc-g2hc-g7m2, UBUNTU-CVE-2026-114216.