VulnerabilityPublished 26 Jan 2026

CVE-2026-24656: Apache Karaf · Deserialization of Untrusted Data

Affects Apache KarafSource CVE Database V5

Not known to be exploited · CVSS 3.7 Low : upgrade to 2.12.0 when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

3.7Low

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.12.0

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

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

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: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Jan 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

Upgrade Apache Karaf and Apache Software Foundation/org.apache.karaf.decanter.collector:org.apache.karaf.decanter.collector.log.socket and org.apache.karaf/apache-karaf-decanter to 2.12.0.

Affected software

Product	Affected	Fixed in
Apache Software FoundationApache Karaf	Affected <2.12.0	Fixed in 2.12.0
MavenApache Software Foundation/org.apache.karaf.decanter.collector:org.apache.karaf.decanter.collector.log.socket`pkg:maven/Apache Software Foundation/org.apache.karaf.decanter.collector:org.apache.karaf.decanter.collector.log.socket`Other threats	Affected <2.12.0	Fixed in 2.12.0
Mavenorg.apache.karaf/apache-karaf-decanter`pkg:maven/org.apache.karaf/apache-karaf-decanter`Other threats	Affected <2.12.0	Fixed in 2.12.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Immediately upgrade Apache Karaf Decanter to version 2.12.0 or later, which contains the fix for this vulnerability.
If upgrading is not immediately possible, disable the Decanter log socket collector component to eliminate exposure.
Restrict network access to port 4560 using firewall rules or network segmentation to limit connections only to trusted hosts.
Review and harden the 'allowed classes' deserialization property configuration to ensure it does not allow bypasses; consider disabling it if not required.
Monitor network traffic and logs for unusual connections or serialized payloads targeting port 4560.
Implement intrusion detection systems (IDS) or endpoint detection and response (EDR) solutions to detect exploitation attempts.
Conduct regular security assessments and penetration tests focusing on deserialization vulnerabilities in custom or third-party components.
Educate development and operations teams about the risks of deserialization of untrusted data and secure coding practices.
Maintain an inventory of Apache Karaf deployments to identify which systems have Decanter installed and prioritize remediation accordingly.

Description

Deserialization of Untrusted Data vulnerability in Apache Karaf Decanter. The Decanter log socket collector exposes the port 4560, without authentication. If the collector exposes allowed classes property, this configuration can be bypassed. It means that the log socket collector is vulnerable to deserialization of untrusted data, eventually causing DoS. NB: Decanter log socket collector is not installed by default. Users who have not installed Decanter log socket are not impacted by this issue. This issue affects Apache Karaf Decanter before 2.12.0. Users are recommended to upgrade to version 2.12.0, which fixes the issue.

Impact

For European organizations using Apache Karaf with the Decanter component enabled, this vulnerability poses a risk of denial of service attacks that could disrupt critical logging and monitoring infrastructure. Since logging is essential for security monitoring, incident response, and compliance, disruption could delay detection of other attacks or system failures. Organizations in sectors such as finance, telecommunications, manufacturing, and government that rely on Apache Karaf for application deployment and monitoring could experience operational downtime or degraded service availability. The lack of authentication on the exposed port increases the attack surface, especially for systems accessible from less trusted networks. Although no remote code execution is confirmed, denial of service can still have significant operational and reputational impacts. The limited default installation of Decanter reduces the overall exposure, but targeted attacks against known deployments remain a concern. Additionally, the bypass of the 'allowed classes' property means that even hardened configurations may be vulnerable, increasing the risk. European organizations with strict uptime and compliance requirements may face regulatory scrutiny if logging systems are compromised or unavailable.

CWE-502Deserialization of Untrusted Data (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #15OWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Architecture and Design · Implementation
If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
Implementation
When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
Implementation
Explicitly define a final object() to prevent deserialization.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
XML Security (opens in a new tab)
XML External Entity Prevention (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.2 (opens in a new tab)
V5.5.3 (opens in a new tab)
V5.5.1 (opens in a new tab)
Attack patterns
Object Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Jan 2026, 10:05 UTC

WeaknessesCWE-502

Technical details

References

Community reviews

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