Deserialization of Untrusted Data in Logback - CVE-2026-9828
Published: July 15, 2026
Vulnerability identifier: #VU137751
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: CVE-2026-9828
CWE-ID: CWE-502
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: QOS.ch
Affected software:
Logback
Logback
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to insecure input validation when processing serialized data in the QOS.CH Sarl logback logback-core (HardenedObjectInputStream (logback-core) modules). A remote 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.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
How to mitigate CVE-2026-9828
Install updates from vendor's website.