CVE-2026-64678

CRITICAL
Published Nov 11, 2026 Modified Nov 12, 2026 CWE-502

Description

NOsql Object (NO2 a.k.a Nitrite) database is an open source nosql embedded document store. Prior to version 4.4.1, when Nitrite opens a database file, MVStoreUtils.openOrCreate() automatically checks for a legacy v1-format store and, on detecting one (or hitting a compatibility error while opening), triggers an automatic migration path. This path deserializes stored values using NitriteDataType.deserialize(byte[]), which passes the raw bytes directly to java.io.ObjectInputStream.readObject() via a custom NitriteObjectInputStream subclass. That subclass overrides only readClassDescriptor() — solely to remap a handful of known legacy class names to their current equivalents — and implements no class allowlist, blocklist, or ObjectInputFilter (JEP 290). Any Serializable class reachable on the embedding application's classpath can therefore be instantiated via readObject(), with readObject()/readExternal()/readResolve() callbacks invoked unconditionally. If a suitable gadget class (e.g. from commons-collections or similar) happens to be present on the classpath, this is a precondition for remote code execution. This issue has been patched in version 4.4.1.

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CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0066
Probability of exploitation
0.52%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-502 Deserialization of Untrusted Data

References

Frequently Asked Questions

What is CVE-2026-64678? +
NOsql Object (NO2 a.k.a Nitrite) database is an open source nosql embedded document store. Prior to version 4.4.1, when Nitrite opens a database file, MVStoreUtils.openOrCreate() automatically checks for a legacy v1-format store and, on detecting one (or hitting a compatibility error while opening), triggers an automatic migration path. This path deserializes stored values using NitriteDataType.deserialize(byte[]), which passes the raw bytes directly to java.io.ObjectInputStream.readObject() via a custom NitriteObjectInputStream subclass. That subclass overrides only readClassDescriptor() — solely to remap a handful of known legacy class names to their current equivalents — and implements no class allowlist, blocklist, or ObjectInputFilter (JEP 290). Any Serializable class reachable on the embedding application's classpath can therefore be instantiated via readObject(), with readObject()/readExternal()/readResolve() callbacks invoked unconditionally. If a suitable gadget class (e.g. from commons-collections or similar) happens to be present on the classpath, this is a precondition for remote code execution. This issue has been patched in version 4.4.1. It has a CVSS v3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2026-64678? +
CVE-2026-64678 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0066, placing it in the 1th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-64678? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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