CVE-2026-9828

CVE-2026-9828 is a low-severity vulnerability with a CVSS 4.0 base score of 2.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-502.

Key facts

Description

Deserialization of untrusted data vulnerability in QOS.CH Sarl logback logback-core (HardenedObjectInputStream (logback-core) modules) allows Object Injection albeit heavily restricted. More precisely, an attacker able to influence serialized data sent to SimpleSocketServer or SimpleSSLSocketServer can instantiate objects from classes in the java.lang and java.util packages that are not explicitly blocked. Although deserialization is heavily restricted by HardenedObjectInputStream and no practical way to achieve remote code execution or significant privilege escalation has been identified, this issue constitutes a bypass of the intended security restrictions. This issue affects logback: through 1.5.32 inclusive.

Frequently asked questions

What is CVE-2026-9828?
Deserialization of untrusted data vulnerability in QOS.CH Sarl logback logback-core (HardenedObjectInputStream (logback-core) modules) allows Object Injection albeit heavily restricted. More precisely, an attacker able to influence serialized data sent to SimpleSocketServer or SimpleSSLSocketServer can instantiate objects from classes in the java.lang and java.util packages that are not explicitly blocked. Although deserialization is heavily restricted by HardenedObjectInputStream and no practical way to achieve remote code execution or significant privilege escalation has been identified, this issue constitutes a bypass of the intended security restrictions. This issue affects logback: through 1.5.32 inclusive.
How severe is CVE-2026-9828?
CVE-2026-9828 has a CVSS 4.0 base score of 2.9, rated low severity.
Is CVE-2026-9828 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-9828?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-9828 have an EU (EUVD) identifier?
Yes. CVE-2026-9828 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32895.
When was CVE-2026-9828 published?
CVE-2026-9828 was published on 2026-05-28 and last updated on 2026-06-17.

References

Other CWE-502 (Deserialization of Untrusted Data) vulnerabilities

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