CVE-2016-6581
- Source
- https://cve.org/CVERecord?id=CVE-2016-6581
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-6581.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2016-6581
- Aliases
- Downstream
- Related
- Published
- 2017-01-10T15:59:00.423Z
- Modified
- 2026-07-08T05:48:18.035575418Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
A HTTP/2 implementation built using any version of the Python HPACK library between v1.0.0 and v2.2.0 could be targeted for a denial of service attack, specifically a so-called "HPACK Bomb" attack. This attack occurs when an attacker inserts a header field that is exactly the size of the HPACK dynamic header table into the dynamic header table. The attacker can then send a header block that is simply repeated requests to expand that field in the dynamic table. This can lead to a gigantic compression ratio of 4,096 or better, meaning that 16kB of data can decompress to 64MB of data on the target machine.
- Database specific
{ "unresolved_ranges": [ { "source": "CPE_STRING", "cpes": [ "cpe:2.3:a:python:hyper:0.4:*:*:*:*:*:*:*", "cpe:2.3:a:python:hyper:0.6:*:*:*:*:*:*:*" ], "vendor_product": "python:hyper", "extracted_events": [ { "introduced": "0.4" }, { "last_affected": "0.4" }, { "introduced": "0.6" }, { "last_affected": "0.6" } ] } ] }- References
Affected packages
Git / github.com/python-hyper/hpack
Affected ranges
- Type
- GIT
- Repo
- https://github.com/python-hyper/hpack
- Events
-
IntroducedLast affected
- Database specific
{ "cpe": [ "cpe:2.3:a:python:hpack:1.0:*:*:*:*:*:*:*", "cpe:2.3:a:python:hpack:2.0:*:*:*:*:*:*:*", "cpe:2.3:a:python:hpack:2.0.1:*:*:*:*:*:*:*", "cpe:2.3:a:python:hpack:2.1.1:*:*:*:*:*:*:*", "cpe:2.3:a:python:hpack:2.2:*:*:*:*:*:*:*" ], "source": "CPE_STRING", "extracted_events": [ { "introduced": "1.0" }, { "last_affected": "1.0" }, { "introduced": "2.0" }, { "last_affected": "2.0" }, { "introduced": "2.0.1" }, { "last_affected": "2.0.1" }, { "introduced": "2.1.1" }, { "last_affected": "2.1.1" }, { "introduced": "2.2" }, { "last_affected": "2.2" } ] }