CVE-2024-11738Public exploitNetwork attack vector

Server crash via unrestored ClientHello deframer cursor

Published Dec 6, 2024 · Updated Nov 20, 2025

Denial of service in Rustls 0.23.13 through 0.23.17 allows remote attackers to crash affected TLS servers via a fragmented ClientHello. Acceptor::accept fails to preserve the deframer buffer's processed cursor while parsing the first handshake message, so fragmented input reaches a panic. Exposure requires rustls Acceptor::accept, tokio-rustls LazyConfigAcceptor, or rustls-ffi rustls_acceptor_accept; tokio-rustls TlsAcceptor is unaffected.

CVSS severity5.3
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Rustls 0.23.13 through 0.23.17 allows remote attackers to crash affected TLS servers via a fragmented ClientHello. Acceptor::accept fails to preserve the deframer buffer's processed cursor while parsing the first handshake message, so fragmented input reaches a panic. Exposure requires rustls Acceptor::accept, tokio-rustls LazyConfigAcceptor, or rustls-ffi rustls_acceptor_accept; tokio-rustls TlsAcceptor is unaffected.

The record

CVE
CVE-2024-11738
Published
Dec 6, 2024
Updated
Nov 20, 2025
Vendor
Rustls
Product
Rustls
Classifications
CWE-248, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 6, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 20, 2025Record 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=0.23.13 <0.23.18

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Rustls · Rustlsversion=0.23.13 <0.23.18

Published CVSS scores

5.3Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
6.9GitHubCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-248Uncaught Exception
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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