CVE-2025-64645VulnerabilityPublished 26 Dec 2025Updated 26 Feb 2026

CVE-2025-64645: IBM Concert · Time-of-check Time-of-use (TOCTOU) Race Condition

Affects IBM ConcertSource CVE Database V5

Not known to be exploited · CVSS 7.7 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.7High

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: None

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
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 impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 2026-10-25.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC 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

Affected software

Product	Affected	Fixed in
IBM Concert	Affected =1.0.0	Fixed in–

AI-suggested

Until an official patch is released, organizations should implement strict local user access controls, limiting the number of users with local system access to the minimum necessary. Employ file system monitoring tools to detect unusual symbolic link creation or modification activities. Use mandatory access control (MAC) frameworks, such as SELinux or AppArmor, to restrict IBM Concert’s ability to follow or create symbolic links. Regularly audit system logs for suspicious behavior indicative of TOCTOU exploitation attempts. Consider deploying endpoint detection and response (EDR) solutions capable of identifying race condition exploitation patterns. Educate system administrators and users about the risks of local privilege escalation and the importance of maintaining least privilege principles. Once available, promptly apply vendor patches and updates. Additionally, isolate IBM Concert installations in segmented network zones to reduce the impact of potential compromises.

Description

IBM Concert 1.0.0 through 2.1.0 could allow a local user to escalate their privileges due to a race condition of a symbolic link.

Impact

The primary impact of CVE-2025-64645 is local privilege escalation, which can lead to unauthorized access to sensitive data and system functions. This compromises confidentiality and integrity, allowing attackers to manipulate or exfiltrate data and potentially install persistent backdoors or malware with elevated rights. Organizations relying on IBM Concert for critical operations may face significant security risks, including insider threats or attackers leveraging compromised local accounts to gain broader system control. Although availability is not directly impacted, the resulting elevated privileges could be used to disrupt services or further propagate attacks. The lack of patches and known exploits increases the urgency for proactive mitigation. Enterprises with multiple users having local access to affected systems are at higher risk, as any local user could attempt exploitation. This vulnerability could also serve as a stepping stone for more complex attacks targeting enterprise infrastructure.

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
Implementation
The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Implementation
When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Architecture and Design
Limit the interleaving of operations on files from multiple processes.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.3 (opens in a new tab)
V11.1.6 (opens in a new tab)
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Race Conditions via Symbolic Links (opens in a new tab)
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

ibm.com/support/pages/node/7255549 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Feb 2026, 06:53 UTC

WeaknessesCWE-367

Technical details

References

Community reviews

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