How severe is CVE-2023-6378?

CVE-2023-6378 has a CVSS score of 7.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2023-6378?

CVE-2023-6378 affects the following packages: ch.qos.logback:logback-classic (Maven), ch.qos.logback:logback-classic (Maven), ch.qos.logback:logback-core (Maven), ch.qos.logback:logback-core (Maven), ch.qos.logback:logback-core (Maven), ch.qos.logback:logback-classic (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-6378?

Update ch.qos.logback:logback-classic to 1.3.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6378 is resolved across your whole dependency graph.

How do I detect CVE-2023-6378 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ch.qos.logback:logback-classic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-6378 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2023-6378 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-6378 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-6378?

CVE-2023-6378 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 60th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-6378?

CVE-2023-6378 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2023-6378 published, and has it been updated?

CVE-2023-6378 was published on November 29, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

HIGH severity

CVE-2023-6378 — logback-classic

HIGHFix: qos-ch/logback@9c782b4

CVE-2023-6378 is a high-severity (CVSS 7.1) Deserialization of Untrusted Data vulnerability in ch.qos.logback:logback-classic. A fix is available for ch.qos.logback:logback-classic — see the affected versions and patch details below.

Logback "receiver" DOS vulnerability

Also known asGHSA-vmq6-5m68-f53m

Published

Nov 29, 2023

Updated

Oct 28, 2026

Affected

6 pkgs

Patched

6 / 6

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-6378.

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs60th percentile — riskier than 60% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

6 pkgs affected

☕ch.qos.logback:logback-classic☕ch.qos.logback:logback-classic☕ch.qos.logback:logback-core☕ch.qos.logback:logback-core☕ch.qos.logback:logback-core☕ch.qos.logback:logback-classic

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

A serialization vulnerability in logback receiver component part of logback allows an attacker to mount a Denial-Of-Service attack by sending poisoned data.

This is only exploitable if logback receiver component is deployed. See https://logback.qos.ch/manual/receivers.html

Affected Packages

6 total 6 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`ch.qos.logback:logback-classic`	≥ 1.3.0&&< 1.3.12	1.3.12`ch.qos.logback:logback-classic:1.3.12`
☕Maven	`ch.qos.logback:logback-classic`	≥ 1.4.0&&< 1.4.12	1.4.12`ch.qos.logback:logback-classic:1.4.12`
☕Maven	`ch.qos.logback:logback-core`	≥ 1.3.0&&< 1.3.12	1.3.12`ch.qos.logback:logback-core:1.3.12`
☕Maven	`ch.qos.logback:logback-core`	≥ 1.4.0&&< 1.4.12	1.4.12`ch.qos.logback:logback-core:1.4.12`
☕Maven	`ch.qos.logback:logback-core`	all versions	1.2.13`ch.qos.logback:logback-core:1.2.13`
☕Maven	`ch.qos.logback:logback-classic`	all versions	1.2.13`ch.qos.logback:logback-classic:1.2.13`

Affected Products

1 product · 3 configurations

Application

logbackqos

≥ 1.4.0 && < 1.4.12

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ch.qos.logback:logback-classic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ch.qos.logback:logback-classic to 1.3.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-6378 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

The Logback package vulnerability, posing a risk of denial-of-service through a serialization flaw in its receiver component, is considered a moderate issue due to its potential impact on system availability. While denial-of-service vulnerabilities can be disruptive, the severity is tempered by the fact that they…

Workaround published by Red Hat

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Source: Red Hat security advisory for CVE-2023-6378 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat AMQ Broker 7	`logback`	RHSA-2024:2945
Red Hat Fuse 7.13.0	`logback`	RHSA-2024:3354
Red Hat OpenShift Dev Spaces 3 Containers	`devspaces/server-rhel8:3.15-3`	RHSA-2024:4631
RHINT Camel-Springboot 4.0.3	`logback`	RHSA-2024:0793

UbuntuHIGH

USN-7616-1Ubuntu

Frequently Asked Questions

A serialization vulnerability in logback receiver component part of logback allows an attacker to mount a Denial-Of-Service attack by sending poisoned data. This is only exploitable if logback receiver component is deployed. See https://logback.qos.ch/manual/receivers.html

O3 Security · Impact-Aware SCA

Is CVE-2023-6378 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

7.1/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

CWE Classification

CWE-502Deserialization of Untrusted Data

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

logback

7.0/10

Maintained10/10

Code-Review1/10

Branch-ProtectionN/A

Assessed Nov 2, 2026

Timeline

Disclosed

Nov 29, 2023

Last updated

Oct 28, 2026

Identifiers

CVE-2023-6378

GHSA-vmq6-5m68-f53m

References

Advisorygithub.com · CVE 2023 6378.json Advisorynvd.nist.gov · CVE 2023 6378 Advisorysecurity.netapp.com · ntap 20241129 0012 Weblogback.qos.ch · news Webgithub.com Webgithub.com · 9c782b45be4abdafb7e17481e24e7354c2acd1eb Webgithub.com · b8eac23a9de9e05fb6d51160b3f46acd91af9731 Webgithub.com · bb095154be011267b64e37a1d401546e7cc2b7c3 Weblogback.qos.ch · receivers Weblogback.qos.ch · news Websecurity.netapp.com · ntap 20241129 0012 Packagegithub.com · logback

Related vulnerabilities

Also affects logback-classic

This CVE is high severity; 1 of 1 other CVE affecting logback-classic is rated as high or higher (top: critical).

CVE-2017-5929

Also affects logback-core

This CVE is high severity; 1 of 7 other CVEs affecting logback-core is rated as high or higher (top: high).

CVE-2026-10532CVE-2026-9828CVE-2026-1225CVE-2025-11226CVE-2024-12801CVE-2024-12798CVE-2023-6481

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 28, 2026

CVE-2023-6378 — logback-classic

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2023-6378 in your dependencies?