Answer in brief
CVE-2023-40175 records a Critical severity (CVSS 9.8) vulnerability in Puma HTTP Request/Response Smuggling vulnerability. The current sources do not mark it as known exploited. The current feed maps puma (rubygems), puma (rubygems). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps puma (rubygems), puma (rubygems). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| pumarubygems | >=0 <5.6.7 | 5.6.7 |
| pumarubygems | >=6.0.0 <6.3.1 | 6.3.1 |
Published upstream
Aug 18, 2023
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Sep 10, 2026
### Impact Prior to version 6.3.1, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies and zero-length Content-Length headers in a way that allowed HTTP request smuggling. The following vulnerabilities are addressed by this advisory: * Incorrect parsing of trailing fields in chunked transfer encoding bodies * Parsing of blank/zero-length Content-Length headers ### Patches The vulnerability has been fixed in 6.3.1 and 5.6.7. ### Workarounds No known workarounds. ### References [HTTP Request Smuggling](https://portswigger.net/web-security/request-smuggling) ### For more information If you have any questions or comments about this advisory: Open an issue in [Puma](https://github.com/puma/puma) See our [security policy](https://github.com/puma/puma/security/policy)
Quoted source text, attributed separately from HOL analysis.