CVE-2023-6481: A serialization vulnerability in logback receiver component part of logback version 1.4.13, 1.3.13 and 1.2.12

Routine

HIGH 7.1DOWNGRADE

CVE-2023-6481 is a high-severity flaw (CVSS 7.1) affecting logback. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A serialization vulnerability in logback receiver component part of logback version 1.4.13, 1.3.13 and 1.2.12 allows an attacker to mount a Denial-Of-Service attack by sending poisoned data.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	No
Published	2023-12-04
Last modified	2026-06-17

Publisher (CNA): Switzerland Government Common Vulnerability Program · Vendor: qos

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-12-04 09:15 UTCPublished CVE record published
2026-06-17 06:50 UTCUpdated Record last modified

qos logback DOWNGRADE

Affected: 1.2.12 · 1.3.13 · 1.4.13

Fixed in: no fixed release known

Safe to downgrade to: a release before 1.2.12

1. Check installed version

apt-cache policy logback || rpm -q logback || logback --version

2. No fixed release: DOWNGRADE to a release before 1.2.12 (Debian / Ubuntu)

apt-cache madison logback sudo apt install logback=<VERSION_BEFORE_1.2.12> sudo apt-mark hold logback

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list logback sudo dnf downgrade logback-<VERSION_BEFORE_1.2.12> sudo dnf versionlock add logback

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-6481?

logback: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-6481 being exploited?

CVE-2023-6481 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-6481 affect?

CVE-2023-6481 affects logback. Severity is high (CVSS 7.1). A serialization vulnerability in logback receiver component part of logback version 1.4.13, 1.3.13 and 1.2.12 allows an attacker to mount a Denial-Of-Service attack by sending poisoned data.

How urgent is CVE-2023-6481?

Priority 38/100. High severity

Related CVEs

CVE-2023-6378 HIGH 7.1 UPGRADE A serialization vulnerability in logback receiver component part of logback version 1.4.11 allows an attacker
CVE-2021-42550 MEDIUM 6.6 UPGRADE DOWNGRADE In logback version 1.2.7 and prior versions, an attacker with the required privileges to edit configurations f
CVE-2017-5929 CRITICAL 9.8 UPGRADE DOWNGRADE QOS.ch Logback before 1.2.0 has a serialization vulnerability affecting the SocketServer and ServerSocketRecei

References

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