CVE-2026-33701: OpenTelemetry Java Instrumentation provides OpenTelemetry auto-instrumentation and instrumentation libraries f

Q: How do I fix CVE-2026-33701?

opentelemetry instrumentation for java: upgrade to 2.26.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-33701 being exploited?

CVE-2026-33701 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-33701 affect?

CVE-2026-33701 affects opentelemetry instrumentation for java. Severity is critical (CVSS 9.8). OpenTelemetry Java Instrumentation provides OpenTelemetry auto-instrumentation and instrumentation libraries for Java. In versions prior to 2.26.1, the RMI instrumentation registered a custom endpoint that deserialized incoming data without

Q: How urgent is CVE-2026-33701?

Priority 62/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

This week

CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-33701 is a critical-severity flaw (CVSS 9.8) affecting opentelemetry instrumentation for java. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

OpenTelemetry Java Instrumentation provides OpenTelemetry auto-instrumentation and instrumentation libraries for Java. In versions prior to 2.26.1, the RMI instrumentation registered a custom endpoint that deserialized incoming data without applying serialization filters. On JDK version 16 and earlier, an attacker with network access to a JMX or RMI port on an instrumented JVM could exploit this to potentially achieve remote code execution. All t

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.9% (top 39%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-03-27
Last modified	2026-08-04

Publisher (CNA): GitHub, Inc. · Vendor: linuxfoundation

Last updated 2026-08-04 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-27 01:16 UTCPublished CVE record published
2026-08-04 13:18 UTCUpdated Record last modified

linuxfoundation opentelemetry instrumentation for java UPGRADE

Affected: < 2.26.1

Fixed in: 2.26.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy opentelemetry-instrumentation-for-java || rpm -q opentelemetry-instrumentation-for-java || opentelemetry-instrumentation-for-java --version

2. UPGRADE to 2.26.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade opentelemetry-instrumentation-for-java

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade opentelemetry-instrumentation-for-java

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Exact fixes by distribution

Maven · io.opentelemetry.javaagent:opentelemetry-javaagent · FIXED · 2.26.1 · vulnerable: < 2.26.1 · source

Set io.opentelemetry.javaagent:opentelemetry-javaagent to 2.26.1 or later in pom.xml or build.gradle, then rebuild and redeploy.

Fedora ELN · perl-Encode · FIXED · 3.25-528.eln159 · FEDORA-2026-79991d0238 · source

sudo dnf upgrade --advisory=FEDORA-2026-79991d0238

Fedora 46 · fonttools · FIXED · 4.68.0-1.fc46 · FEDORA-2026-65d6c01c75 · source

sudo dnf upgrade --advisory=FEDORA-2026-65d6c01c75

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: pl4tyz/CVE-2026-33701-Unsafe-Deserialization-in-OpenTelemetry-Java-Agent-RMI-Instrumentation (0 stars)

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-2026-33701?

opentelemetry instrumentation for java: upgrade to 2.26.1. Exact commands for each OS are on this page.

Is CVE-2026-33701 being exploited?

CVE-2026-33701 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-2026-33701 affect?

CVE-2026-33701 affects opentelemetry instrumentation for java. Severity is critical (CVSS 9.8). OpenTelemetry Java Instrumentation provides OpenTelemetry auto-instrumentation and instrumentation libraries for Java. In versions prior to 2.26.1, the RMI instrumentation registered a custom endpoint that deserialized incoming data without

How urgent is CVE-2026-33701?

Priority 62/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Java vulnerabilities

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References

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