VulnerabilityPublished 4 Feb 2026

CVE-2024-51451: IBM Concert · Improper Neutralization of HTTP Headers for Scripting Syntax

Affects IBM ConcertSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, 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: 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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on 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 4 Feb 2026
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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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

Affected software

Product	Affected	Fixed in
IBMConcert	Affected >=1.0.0 <=2.1.0	Fixed in–

CPE configurations (2)

cpe:2.3:a:ibm:concert:1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:concert:2.1.0:*:*:*:*:*:*:*

AI-suggested

Organizations should implement strict input validation and sanitization of HOST headers at the application level to prevent injection of malicious content. Deploying web application firewalls (WAFs) with custom rules to detect and block suspicious HOST header manipulations can provide an effective network-level defense. Monitoring HTTP traffic for anomalies related to header values can help detect exploitation attempts early. Since no official patches are currently available, organizations should engage with IBM support for guidance and apply any forthcoming updates promptly. Additionally, restricting access to IBM Concert instances via network segmentation and VPNs can reduce exposure. Educating users about the risks of suspicious links and maintaining robust session management policies will help mitigate session hijacking risks. Regular security assessments and penetration testing focused on HTTP header injection vulnerabilities are recommended to identify and remediate weaknesses proactively.

Description

CVE-2024-51451 is a medium severity vulnerability in IBM Concert versions 1.0.0 through 2.1.0 caused by improper validation of HOST headers, leading to HTTP header injection. This flaw allows attackers to perform cross-site scripting (XSS), cache poisoning, or session hijacking without requiring authentication or user interaction. The vulnerability impacts confidentiality and integrity but not availability. Exploitation is remotely feasible with low complexity. European organizations using IBM Concert, especially in countries with significant IBM enterprise deployments, are at risk. Mitigations include strict validation and sanitization of HOST headers, deploying web application firewalls with custom rules, and monitoring HTTP traffic for anomalies.

Impact

For European organizations, exploitation of CVE-2024-51451 could lead to unauthorized disclosure of sensitive information through XSS attacks, undermining confidentiality. Cache poisoning could disrupt content delivery and trust in web services, potentially affecting business operations and user experience. Session hijacking could allow attackers to impersonate legitimate users, leading to data manipulation or unauthorized actions within the IBM Concert platform. These impacts are particularly critical for sectors handling sensitive or regulated data, such as finance, healthcare, and government. The lack of required authentication and user interaction lowers the barrier for attackers, increasing the risk of widespread exploitation. Additionally, compromised collaboration platforms can disrupt organizational workflows and damage reputations. Given IBM Concert’s use in enterprise environments, the threat could extend to supply chain partners and clients, amplifying the impact.

Summary

CVE-2024-51451 is a vulnerability classified under CWE-644, which involves improper neutralization of HTTP headers for scripting syntax in IBM Concert versions 1.0.0 through 2.1.0. The root cause is insufficient validation of the HOST header input, which allows an attacker to inject malicious content into HTTP headers. This injection can facilitate several attack vectors, including cross-site scripting (XSS), where malicious scripts execute in the context of the victim's browser; cache poisoning, which can cause users to receive malicious or stale content; and session hijacking, enabling attackers to steal or manipulate user sessions. The vulnerability is remotely exploitable over the network without requiring any privileges or user interaction, making it relatively easy to exploit. The CVSS 3.1 base score is 6.5, indicating a medium severity level, with impacts primarily on confidentiality and integrity but not availability. No patches or exploits are currently publicly available, but the risk remains significant due to the potential for these attacks to compromise user data and trust. IBM Concert is an enterprise collaboration platform, and its compromise could affect sensitive communications and workflows.

CWE-644Improper Neutralization of HTTP Headers for Scripting Syntax (opens in a new tab)
Variant weaknessLikelihood of exploit: HighOWASP Top 10 A05:2025: Injection (opens in a new tab)
The product does not neutralize or incorrectly neutralizes web scripting syntax in HTTP headers that can be used by web browser components that can process raw headers, such as Flash.
Architecture and Design
Perform output validation in order to filter/escape/encode unsafe data that is being passed from the server in an HTTP response header.
Architecture and Design
Disable script execution functionality in the clients' browser.
OWASP Cheat Sheets
Content Security Policy (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
Query Parameterization (opens in a new tab)
OWASP ASVS 4.0.3
V14.4.6 (opens in a new tab)
V14.4.4 (opens in a new tab)
V14.4.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

ibm.com/support/pages/node/7257006 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

CPE configurations (2)

Description

AI analysisMachine-generated, updated 12 Feb 2026, 07:32 UTC

WeaknessesCWE-644

Technical details

References

Community reviews

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