CVE WatchAug 11, 2026

CVE-2023-44487

HTTP/2 Rapid Reset Attack Vulnerability

CVSS

7.5

High

EPSS

100.0%

p100

KEV

YES

Oct 10, 2023

Exploit Today

0-100

Published: Oct 10, 2023 · Last modified: Aug 11, 2026 · CWE-400

EPSS · 30d

100.0%EPSS · 30 days100.0%

2026-09-162026-10-14

KEV catalog record

Product

IETF / HTTP/2

Vulnerability

HTTP/2 Rapid Reset Attack Vulnerability

Added to KEV

Oct 10, 2023

Remediate by

Oct 31, 2023

Known ransomware use

Summary description

HTTP/2 contains a rapid reset vulnerability that allows for a distributed denial-of-service attack (DDoS).

Required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Notes

This vulnerability affects a common open-source component, third-party library, or protocol used by different products. For more information, please see: HTTP/2 Rapid Reset Vulnerability, CVE-2023-44487 | CISA: https://www.cisa.gov/news-events/alerts/2023/10/10/http2-rapid-reset-vulnerability-cve-2023-44487; https://blog.cloudflare.com/technical-breakdown-http2-rapid-reset-ddos-attack/; https://nvd.nist.gov/vuln/detail/CVE-2023-44487

Technical description

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

Official references

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