CVE-2025-55084Network attack vector

Information disclosure via odd-length TLS version list

Published Oct 16, 2025 · Updated Oct 16, 2025

Buffer over-read in Eclipse ThreadX NetX Duo before 6.4.4 allows remote attackers to disclose memory via a crafted TLS ClientHello. The supported-versions parser validates the one-byte list length but iterates in two-byte steps, so an odd-length list makes the final read consume one byte beyond the extension. A reachable NetX Secure TLS server and a malformed unauthenticated ClientHello are required; the disclosed byte depends on adjacent memory.

CVSS severity6.9
Medium
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

Buffer over-read in Eclipse ThreadX NetX Duo before 6.4.4 allows remote attackers to disclose memory via a crafted TLS ClientHello. The supported-versions parser validates the one-byte list length but iterates in two-byte steps, so an odd-length list makes the final read consume one byte beyond the extension. A reachable NetX Secure TLS server and a malformed unauthenticated ClientHello are required; the disclosed byte depends on adjacent memory.

The record

CVE
CVE-2025-55084
Published
Oct 16, 2025
Updated
Oct 16, 2025
Vendor
The Eclipse Foundation
Product
Eclipse ThreadX NetX Duo
Classifications
CWE-126, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 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 <6.4.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Eclipse Foundation · Eclipse ThreadX NetX Duoversion=0 <6.4.4

Published CVSS scores

6.9Eclipse FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-126Buffer Over-read
T1190Exploit Public-Facing Application

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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