Resource exhaustion vulnerability in h2 may lead to Denial of Service (DoS)
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Fixed
No CVSS vector from any source. Fix status from GitHub.
Summary
An attacker with an HTTP/2 connection to an affected endpoint can send a steady stream of invalid frames to force the generation of reset frames on the victim endpoint. By closing their recv window, the attacker could then force these resets to be queued in an unbounded fashion, resulting in Out Of Memory (OOM) and high CPU usage. This fix is corrected in [hyperium/h2#737](https://github.com/hyperium/h2/pull/737), which limits the total number of internal error resets emitted by default before the connection is closed.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | h2 (crates.io) | before 0.3.24 | 0.3.24 | Patch available | GHSA-8r5v-vm4m-4g25 |
| — | h2 (crates.io) | 0.4.0 to before 0.4.2 | 0.4.2 | Patch available | GHSA-8r5v-vm4m-4g25 |
- h2 (crates.io) Vendor— Affected before 0.3.24 Fixed in 0.3.24 Patch available GHSA-8r5v-vm4m-4g25
- h2 (crates.io) Vendor— Affected 0.4.0 to before 0.4.2 Fixed in 0.4.2 Patch available GHSA-8r5v-vm4m-4g25
Remediation
- Fix · GHSA-8r5v-vm4m-4g25 h2 (crates.io) Fixed in 0.3.24 Advisory →
- Fix · GHSA-8r5v-vm4m-4g25 h2 (crates.io) Fixed in 0.4.2 Advisory →
Timeline
- 2026-10-03 Threatist record created from GHSA-8r5v-vm4m-4g25
References
Sources
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