high Known exploitedREV. 01

CVE-2023-44487HTTP/2 Rapid Reset — Denial of Service by Stream Cancellation

A weakness in the second version of the web's transfer protocol (HTTP/2) lets a client open and cancel streams faster than a server can clean them up, exhausting it over very few connections.

YOUR NEXT MOVE

Apply your web server or proxy vendor's Rapid Reset patch, and cap concurrent streams and resets per connection.

Read the risk

THE VITAL STATS
CVSS score
7.5/ 10
CVSS v3.1
EPSS probability
100%
Likelihood of exploitation
Attack complexity
Low
Conditions needed to exploit
Known exploited
Yes — CISA KEV
CVE published
2023-10-10
Added to KEV
2023-10-10
Exploit published
Yes
Confidence
high
Kill chain
impact
MITRE ATT&CK
T1499
Severity
high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attacker needsThe ability to open connections to the server

Behind the card

5 REFERENCES
Field-level provenanceTRACE THE SOURCES +

Which source supports each field, when it was retrieved, and who extracted it.

FieldsSourceRetrievedExtractorConfidence
cvss, exploitation.attack_complexity, exploitation.exploit_available, references, published_atnvd.nist.gov2026-08-07scrty-crds-pipeline/0.1high
exploitation.known_exploited, exploitation.kev_addedcisa.gov2026-08-07scrty-crds-pipeline/0.1high
epssapi.first.org2026-08-07scrty-crds-pipeline/0.1high
title, summary, severity, remediation, mitre_attack, kill_chain, recommended_action, confidence, tags, exploitation.prerequisitesnvd.nist.gov2026-08-07claude-codehigh

Printing history

THE RECORD
  1. r1Initial base card

First printing. This card has not been reprinted since publication.

crds:cve-2023-44487 · CRDS 0.1 · Issued 2026-08-07