CVE-2026-44602Network attack vector

Remote daemon crash via out-of-order CERT cell

Published May 7, 2026 · Updated May 7, 2026

NULL pointer dereference in Tor before 0.4.9.7 allows remote attackers to crash a relay daemon with an out-of-order CERT cell. The relay link-handshake path processes the CERT cell before prerequisite handshake state exists and dereferences a missing pointer. No authentication or user interaction is required, but the peer must induce the unexpected cell ordering; the resulting impact is a Tor process crash and service interruption.

CVSS severity3.7
Low
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Tor before 0.4.9.7 allows remote attackers to crash a relay daemon with an out-of-order CERT cell. The relay link-handshake path processes the CERT cell before prerequisite handshake state exists and dereferences a missing pointer. No authentication or user interaction is required, but the peer must induce the unexpected cell ordering; the resulting impact is a Tor process crash and service interruption.

The record

CVE
CVE-2026-44602
Published
May 7, 2026
Updated
May 7, 2026
Vendor
The Tor Project
Product
Tor
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 7, 2026CVE publishedPublication date reported by the CVE source.
  2. May 7, 2026Record 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 <0.4.9.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Tor Project · Torversion=0 <0.4.9.7

Published CVSS scores

3.7MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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