Vulnerability · Published May 12, 2026 · Assigned by GitHub_M
CVE-2026-42545Granian: DoS via WSGI response header panic
Medium 5.9
In plain English
A medium-severity security flaw in granian from emmett-framework. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Granian is a Rust HTTP server for Python applications. From 0.2.0 to 2.7.4, Granian aborts a worker process if a WSGI application returns an invalid HTTP response header name or value. The WSGI response conversion path uses .unwrap() on both the header name and header value constructors, so malformed output from the application becomes a process abort instead of a handled error. This vulnerability is fixed in 2.7.4.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | granian | 2.7.4 | GHSA-f5p7-9fr5-8jmj |
| PyPI | granian | 2.7.4 | PYSEC-2026-2502 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| emmett-framework | granian | >= 0.2.0, < 2.7.4 |
Weakness: CWE-248, CWE-755 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H