The ObjectSerializationDecoder in Apache MINA uses Java’s native deserialization protocol to process
incoming serialized data but lacks the necessary security checks and defenses. This vulnerability allows
attackers to exploit the deserialization process by sending specially crafted malicious serialized data,
potentially leading to remote code execution (RCE) attacks.
This issue affects MINA core versions 2.0.X, 2.1.X and 2.2.X, and will be fixed by the releases 2.0.27, 2.1.10 and 2.2.4.
It's also important to note that an application using MINA core library will only be affected if the IoBuffer#getObject() method is called, and this specific method is potentially called when adding a ProtocolCodecFilter instance using the ObjectSerializationCodecFactory class in the filter chain. If your application is specifically using those classes, you have to upgrade to the latest version of MINA core library.
Upgrading will not be enough: you also need to explicitly allow the classes the decoder will accept in the ObjectSerializationDecoder instance, using one of the three new methods:
/**
* Accept class names where the supplied ClassNameMatcher matches for
* deserialization, unless they are otherwise rejected.
*
* @param classNameMatcher the matcher to use
*/
public void accept(ClassNameMatcher classNameMatcher)
/**
* Accept class names that match the supplied pattern for
* deserialization, unless they are otherwise rejected.
*
* @param pattern standard Java regexp
*/
public void accept(Pattern pattern)
/**
* Accept the wildcard specified classes for deserialization,
* unless they are otherwise rejected.
*
* @param patterns Wildcard file name patterns as defined by
* {@link org.apache.commons.io.FilenameUtils#wildcardMatch(String, String) FilenameUtils.wildcardMatch}
*/
public void accept(String... patterns)
By default, the decoder will reject *all* classes that will be present in the incoming data.
Note: The FtpServer, SSHd and Vysper sub-project are not affected by this issue.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 24% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-02). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it