Logback deserialization whitelist bypass for java.lang and java.util_CVE-2026-9828

1.2 / 10

LOW

CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:P/RE:L/U:Green

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.

Basic Information

ID CVE-2026-9828

Source NCSC.ch

Published May 28, 2026 at 12:52

Affected Product

Vendor QOS.CH Sarl

Product logback

Affected Versions QOS.CH Sarl logback 0

CWE Classification

CWE-502

References

logback.qos.ch /news.html

{
    "lastseen": "",
    "description": "Deserialization of untrusted data vulnerability in QOS.CH Sarl logback logback-core (HardenedObjectInputStream (logback-core) modules) allows Object Injection albeit heavily restricted.\n\nMore precisely, an attacker able to influence serialized data sent to \nSimpleSocketServer or SimpleSSLSocketServer can instantiate objects from\n classes in the java.lang and java.util packages that are not explicitly\n blocked.\n\nAlthough deserialization is heavily restricted by HardenedObjectInputStream and no \npractical way to achieve remote code execution or significant privilege \nescalation has been identified, this issue constitutes a bypass of the \nintended security restrictions.\n\n\n\nThis issue affects logback: through 1.5.32 inclusive.",
    "published": "2026-05-28T12:52:45.852Z",
    "modified": "2026-05-28T12:52:45.852Z",
    "type": "cve",
    "title": "Logback deserialization whitelist bypass for java.lang and java.util",
    "source": "NCSC.ch",
    "references": "https://logback.qos.ch/news.html#1.5.33",
    "id": "CVE-2026-9828",
    "bulletinFamily": "",
    "cwe": [
        "CWE-502"
    ],
    "cvelist": null,
    "sourceData": "QOS.CH Sarl logback 0",
    "sourceHref": "",
    "cvss": {
        "score": 1.2,
        "severity": "LOW",
        "vector": "CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:P/RE:L/U:Green",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "logback",
    "version": "0",
    "vendor": "QOS.CH Sarl",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}