CVE-2024-52811Network attack vector

Memory corruption via unvalidated ACK qlog write

Published Nov 25, 2024 · Updated Nov 25, 2024

Heap buffer overflow in ngtcp2 1.9.0 allows remote attackers to corrupt memory in qlog-enabled QUIC applications with a malformed ACK frame. conn_recv_pkt skips ngtcp2_pkt_validate_ack after an ACK was already processed, yet write_ack_frame logs that invalid ACK and underallocates its range text after an integer underflow. Exploitation requires qlog, which is disabled by default; the overwrite can alter memory and interrupt the embedding application's service.

CVSS severity8.2
High
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap buffer overflow in ngtcp2 1.9.0 allows remote attackers to corrupt memory in qlog-enabled QUIC applications with a malformed ACK frame. conn_recv_pkt skips ngtcp2_pkt_validate_ack after an ACK was already processed, yet write_ack_frame logs that invalid ACK and underallocates its range text after an integer underflow. Exploitation requires qlog, which is disabled by default; the overwrite can alter memory and interrupt the embedding application's service.

The record

CVE
CVE-2024-52811
Published
Nov 25, 2024
Updated
Nov 25, 2024
Vendor
ngtcp2
Product
ngtcp2
Classifications
CWE-670, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 25, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 25, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion== 1.9.0
  2. Affected versionversion=1.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ngtcp2 · ngtcp2version== 1.9.0; version=1.9.0

Published CVSS scores

8.2GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-670Always-Incorrect Control Flow Implementation
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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