CVE-2026-28256Network attack vector

Account takeover via hardcoded cryptographic keys

Published Mar 12, 2026 · Updated Mar 12, 2026

Hardcoded cryptographic constants in Trane Tracer SC, Tracer SC+, and Tracer Concierge allow attackers to decrypt sensitive data. The controllers store a shared Blowfish configuration key and backup and firmware keys on disk, including in /dev/mmcblk0boot0, allowing protected values to be decrypted and firmware to be forged. Access to the key material requires high privileges on a controller; recovered secrets can expose configuration data and support account takeover or malicious firmware signing.

CVSS severity9.8
Critical
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hardcoded cryptographic constants in Trane Tracer SC, Tracer SC+, and Tracer Concierge allow attackers to decrypt sensitive data. The controllers store a shared Blowfish configuration key and backup and firmware keys on disk, including in /dev/mmcblk0boot0, allowing protected values to be decrypted and firmware to be forged. Access to the key material requires high privileges on a controller; recovered secrets can expose configuration data and support account takeover or malicious firmware signing.

The record

CVE
CVE-2026-28256
Published
Mar 12, 2026
Updated
Mar 12, 2026
Vendor
Trane
Product
Tracer SC
Classifications
CWE-547, T1552.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 12, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 12, 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 <v4.4 SP7
  2. Affected versionversion=0 <v6.3.2310

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Trane · Tracer SCversion=0 <v4.4 SP7; version=0 <v6.3.2310
Trane · Tracer Conciergeversion=0 <v6.3.2310

Published CVSS scores

6.9ICS-CERTCVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-547Use of Hard-coded, Security-relevant Constants
T1552.004Unsecured Credentials: Private Keys

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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