QOS.CH Sarl logback logback-core has a deserialization of untrusted data vulnerability (CVE-2026-9828) | HOL Guard CVE

Low severityCVE-2026-9828GHSA-P47F-322F-WHFH

QOS.CH Sarl logback logback-core has a deserialization of untrusted data vulnerability

Answer in brief

CVE-2026-9828 records a Low severity vulnerability in QOS.CH Sarl logback logback-core has a deserialization of untrusted data vulnerability. The current sources do not mark it as known exploited. The current feed maps ch.qos.logback:logback-core (maven), ch.qos.logback:logback-core (maven). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published May 28, 2026Updated Sep 10, 2026Source checked Sep 17, 2026First seen by HOL Jul 2, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Low
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps ch.qos.logback:logback-core (maven), ch.qos.logback:logback-core (maven). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
ch.qos.logback:logback-coremaven	<=1.5.32	1.5.33
ch.qos.logback:logback-coremaven	>=0 <1.5.33	1.5.33

Recommended response

Check inventory. Check lockfiles and deployed manifests for ch.qos.logback:logback-core, ch.qos.logback:logback-core.
Review the reported fix. Update ch.qos.logback:logback-core to 1.5.33; ch.qos.logback:logback-core to 1.5.33 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
May 28, 2026
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Jul 2, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.