CVE-2026-29181: OpenTelemetry-Go is the Go implementation of OpenTelemetry

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-29181 is a high-severity flaw (CVSS 7.5) affecting opentelemetry. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

OpenTelemetry-Go is the Go implementation of OpenTelemetry. From 1.36.0 to 1.40.0, multi-value baggage: header extraction parses each header field-value independently and aggregates members across values. This allows an attacker to amplify cpu and allocations by sending many baggage: header lines, even when each individual value is within the 8192-byte per-value parse limit. This vulnerability is fixed in 1.41.0.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-770
Published	2026-04-07
Last modified	2026-09-11

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

Last updated 2026-09-11 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-07 21:17 UTCPublished CVE record published
2026-09-11 13:17 UTCUpdated Record last modified

opentelemetry opentelemetry UPGRADE

Affected: >= 1.36.0 and < 1.41.0

Fixed in: 1.41.0

Safe to downgrade to: a release before 1.36.0

1. Check installed version

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

2. UPGRADE to 1.41.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade opentelemetry

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade opentelemetry

Note

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

3. If no update is available yet, DOWNGRADE to a release before 1.36.0 (Debian / Ubuntu)

apt-cache madison opentelemetry sudo apt install opentelemetry=<VERSION_BEFORE_1.36.0> sudo apt-mark hold opentelemetry

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list opentelemetry sudo dnf downgrade opentelemetry-<VERSION_BEFORE_1.36.0> sudo dnf versionlock add opentelemetry

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-2026-29181?

opentelemetry: upgrade to 1.41.0. Exact commands for each OS are on this page.

Is CVE-2026-29181 being exploited?

CVE-2026-29181 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-2026-29181 affect?

CVE-2026-29181 affects opentelemetry. Severity is high (CVSS 7.5). OpenTelemetry-Go is the Go implementation of OpenTelemetry. From 1.36.0 to 1.40.0, multi-value baggage: header extraction parses each header field-value independently and aggregates members across values. This allows an attacker to amplify

How urgent is CVE-2026-29181?

Priority 50/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

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References

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