Cyber Resilience

CVE-2026-9828

Low

Published: 28 May 2026

Published
28 May 2026
Modified
29 May 2026
KEV Added
Patch
CVSS Score v4 2.9 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:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:L/U:Green
EPSS Score 0.0011 29.5th percentile
Risk Priority 6 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-9828 is a low-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Qos (inferred from references). Its CVSS base score is 2.9 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Deserialization flaw in exposed socket servers directly enables exploitation of a public-facing application (T1190).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

Affected Assets

Qos
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-502

Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.

addresses: CWE-502

Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.

addresses: CWE-502

Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.

addresses: CWE-502

Validates or rejects untrusted serialized data before deserialization occurs.

addresses: CWE-502

Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.

addresses: CWE-502

Integrity verification of serialized information can detect tampering before deserialization occurs.

addresses: CWE-502

Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.

References