VulnerabilityPublished 12 Mar 2026

CVE-2026-28253: Trane Tracer SC · Excessive Memory Allocation

Affects Trane Tracer SCSource CVE Database V5

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Not known to be exploited · CVSS 8.7 High : upgrade to v4.4 SP7 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 4.0 base score

8.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in v4.4 SP7, v6.3.2310

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: High
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Tracer to v4.4 SP7 (SC) or v6.3.2310 (SC+, Concierge).

Affected software

Product	Affected	Fixed in
TraneTracer SC	Affected =0	Fixed in v4.4 SP7
TraneTracer SC+	Affected <6.3.2310	Fixed in v6.3.2310
TraneTracer Concierge	Affected <6.3.2310	Fixed in v6.3.2310

AI-suggested

Implement network-level access controls to restrict exposure of Trane Tracer SC systems to untrusted networks, including segmentation and firewall rules limiting inbound traffic to trusted sources only.
Monitor network traffic for anomalous or excessive memory allocation requests targeting Trane systems, using IDS/IPS solutions with custom signatures if possible.
Employ rate limiting or connection throttling on interfaces exposed to external networks to reduce the risk of resource exhaustion attacks.
5. Conduct regular system and network audits to identify and isolate vulnerable Trane devices, prioritizing remediation or temporary isolation. 6. Consider deploying application-layer gateways or proxies that can validate and sanitize incoming requests to Trane systems, preventing malformed or oversized allocation requests. 7. Develop incident response plans specific to building management system disruptions to ensure rapid recovery and mitigation of DoS events. 8. Where possible, implement redundancy and failover mechanisms for critical building management functions to maintain availability during attacks.

Description

CVE-2026-28253 is a high-severity vulnerability in Trane Tracer SC, Tracer SC+, and Tracer Concierge building management systems. It involves a memory allocation flaw where an attacker can request excessive memory allocation, leading to denial-of-service (DoS) conditions. The vulnerability requires no authentication or user interaction and can be exploited remotely over the network. While no known exploits are currently in the wild, the CVSS score of 8.7 reflects the significant risk posed by this flaw. The vulnerability impacts availability by potentially crashing or severely degrading the affected systems. Trane Tracer products are widely used in commercial and industrial HVAC and building automation, making this a critical concern for organizations relying on these systems. Mitigation requires careful input validation and memory allocation controls, though no patches are currently available. Countries with extensive deployment of Trane building management solutions and critical infrastructure reliance on such systems are at higher risk. Immediate defensive measures and monitoring are recommended to prevent exploitation.

Impact

The primary impact of CVE-2026-28253 is a denial-of-service condition that can disrupt building management systems controlling HVAC, security, and other critical infrastructure functions. Organizations using Trane Tracer SC products could experience system crashes or unresponsiveness, leading to operational downtime, reduced occupant comfort, and potential safety risks. In environments such as hospitals, data centers, manufacturing plants, and commercial buildings, such disruptions could have cascading effects on business continuity and safety compliance. The vulnerability's ease of exploitation without authentication means attackers can launch DoS attacks remotely, increasing the threat surface. Although no data confidentiality or integrity loss is indicated, the availability impact alone can cause significant operational and financial damage. The lack of current patches further exacerbates the risk, requiring organizations to implement compensating controls. The vulnerability also raises concerns about potential future exploitation or chaining with other vulnerabilities to escalate impact.

CWE-789Memory Allocation with Excessive Size Value (opens in a new tab)
Variant weakness
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
Implementation · Architecture and Design
Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
Operation
Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V8.1.4 (opens in a new tab)
V13.4.1 (opens in a new tab)
V11.1.4 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

cisa.gov/news-events/ics-advisories/icsa-26-071-01 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 20 Mar 2026, 02:29 UTC

WeaknessesCWE-789

Technical details

References

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