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Case File

CVE-2025-4820

MEDIUM · CVSS 5.3 EPSS 0.77% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2025-06-18 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 5.3. Public exploit code or proof-of-concept references have been detected in its references. It may be remotely exploitable.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2025-4820
Severity
MEDIUM
CVSS
5.3
EPSS
0.77%

Original NVD Description

Impact Cloudflare quiche was discovered to be vulnerable to incorrect congestion window growth, which could cause it to send data at a rate faster than the path might actually support. An unauthenticated remote attacker can exploit the vulnerability by first completing a handshake and initiating a congestion-controlled data transfer towards itself. Then, it could manipulate the victim's congestion control state by sending ACK frames exercising an opportunistic ACK attack; see RFC 9000 Section 21.4. The victim could grow the congestion window beyond typical expectations and allow more bytes in flight than the path might really support. Patches quiche 0.24.4 is the earliest version containing the fix for this issue.

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