Answer in brief
CVE-2024-21647 records a Medium severity (CVSS 5.9) 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 5.9. 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 | >=6.0.0 <6.4.2 | 6.4.2 |
| pumarubygems | >=0 <5.6.8 | 5.6.8 |
Published upstream
Jan 8, 2024
Evidence: source:osv:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Aug 7, 2026
### Impact Prior to versions 6.4.2 and 5.6.8, puma exhibited dangerous behavior when parsing chunked transfer encoding bodies. Fixed versions limit the size of chunk extensions. Without this limit, an attacker could cause unbounded resource (CPU, network bandwidth) consumption. ### Patches The vulnerability has been fixed in 6.4.2 and 5.6.8. ### Workarounds No known workarounds. ### References * [HTTP Request Smuggling](https://portswigger.net/web-security/request-smuggling) * 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.