CVE-2026-44600Network attack vector

Relay service interruption via stale queue accounting

Published May 7, 2026 · Updated May 7, 2026

Incorrect behavior order in Tor before 0.4.9.7 allows remote attackers to interrupt relay service through Conflux traffic. conflux_clear_ooo_q frees queued relay messages and clears the list without subtracting their allocations from total_ooo_q_bytes, leaving global memory accounting inflated. Exploitation requires remote attackers to induce out-of-order Conflux traffic and queue teardown; the reported consequence is limited to relay availability.

CVSS severity3.7
Low
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect behavior order in Tor before 0.4.9.7 allows remote attackers to interrupt relay service through Conflux traffic. conflux_clear_ooo_q frees queued relay messages and clears the list without subtracting their allocations from total_ooo_q_bytes, leaving global memory accounting inflated. Exploitation requires remote attackers to induce out-of-order Conflux traffic and queue teardown; the reported consequence is limited to relay availability.

The record

CVE
CVE-2026-44600
Published
May 7, 2026
Updated
May 7, 2026
Vendor
The Tor Project
Product
Tor
Classifications
CWE-696, T1499
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
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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-696Incorrect Behavior Order
T1499Endpoint Denial of Service

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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