GHSA-q6cp-qfwq-4gcv
h2 servers vulnerable to degradation of service with CONTINUATION Flood
GHSA-q6cp-qfwq-4gcv is a medium vulnerability (CVSS 5.3) in h2, published April 3, 2024. No source lists public exploit code. Fixed in h2 0.3.26.
- Severity
- 5.3 MediumCVSS 3.1, GitHub Advisories
- Exploit chance
- UnscoredNo EPSS score yet
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
0.3.26h2 +2 more
Description
An attacker can send a flood of CONTINUATION frames, causing h2 to process them indefinitely. This results in an increase in CPU usage.
Tokio task budget helps prevent this from a complete denial-of-service, as the server can still respond to legitimate requests, albeit with increased latency.
More details at https://seanmonstar.com/blog/hyper-http2-continuation-flood/.
Patches available for 0.4.x and 0.3.x versions.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Affected packages
What each source reports
GitHub Advisories Score used
h2 servers vulnerable to degradation of service with CONTINUATION Flood
An attacker can send a flood of CONTINUATION frames, causing h2 to process them indefinitely. This results in an increase in CPU usage.
Tokio task budget helps prevent this from a complete denial-of-service, as the server can still respond to legitimate requests, albeit with increased latency.
More details at https://seanmonstar.com/blog/hyper-http2-continuation-flood/.
Patches available for 0.4.x and 0.3.x versions.
- Record
GHSA-q6cp-qfwq-4gcv- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
OSV
h2 servers vulnerable to degradation of service with CONTINUATION Flood
An attacker can send a flood of CONTINUATION frames, causing h2 to process them indefinitely. This results in an increase in CPU usage.
Tokio task budget helps prevent this from a complete denial-of-service, as the server can still respond to legitimate requests, albeit with increased latency.
More details at https://seanmonstar.com/blog/hyper-http2-continuation-flood/.
Patches available for 0.4.x and 0.3.x versions.
- Record
GHSA-q6cp-qfwq-4gcv- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-400, CWE-770
- Updated
- 2026-11-02
OSVRUSTSEC-2024-0332No score
Degradation of service in h2 servers with CONTINUATION Flood
An attacker can send a flood of CONTINUATION frames, causing h2 to process them indefinitely.
This results in an increase in CPU usage.
Tokio task budget helps prevent this from a complete denial-of-service, as the server can still respond to legitimate requests, albeit with increased latency.
More details at "https://seanmonstar.com/blog/hyper-http2-continuation-flood/.
Patches available for 0.4.x and 0.3.x versions.
- Record
RUSTSEC-2024-0332- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | GitHub Advisories, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.