Public proof of conceptFix available

CVE-2026-29181

Q: Is CVE-2026-29181 actively exploited?

A proof-of-concept exploit exists for CVE-2026-29181, but active exploitation has not been confirmed at this time.

Q: What is the CVSS score for CVE-2026-29181?

CVE-2026-29181 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

A public proof of concept exists; no exploitation attested.

Published2026-04-07
Fixed in1.41.0
WeaknessCWE-770

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC

2026-04-0721:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-29181?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-29181?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV

Opentelemetry

Branch	Affected	Fixed in	Source
1.x	≥ 1.36.0, < 1.41.0	1.41.0	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

CVE-2026-29181 Red Hat Product Security48 products fixed · 11 known affected
github.com/open-telemetry/opentelemetry-go: OpenTelemetry-Go: Denial of Service via crafted multi-value baggage headers
cert-manager/jetstack-cert-manager-rhel9 as a component of cert-manager Operator for Red Hat OpenShift · multicluster-engine/assisted-installer-agent-rhel9 as a component of Multicluster Engine for Kubernetes · multicluster-engine/assisted-service-9-rhel9 as a component of Multicluster Engine for Kubernetes · +8 more
RHSA-2026:83013 Red Hat Product Security4 products fixed
Red Hat Security Advisory: Logging for Red Hat OpenShift - 6.0.17
RHSA-2026:82336 Red Hat Product Security4 products fixed
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.17.1
RHSA-2026:82322 Red Hat Product Security4 products fixed
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.17.2
RHSA-2026:72475 Red Hat Product Security4 products fixed
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.20.1
RHSA-2026:72395 Red Hat Product Security4 products fixed
Red Hat Security Advisory: cert-manager Operator for Red Hat OpenShift 1.20.1

7 more advisories

Full record on NVD

Fix

Update Opentelemetry to 1.41.0
Vendor fix Red Hat Product Security RHSA-2026:83013 · 4 productsFor OpenShift Container Platform 4.16 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.16/html/relea…
Vendor fix Red Hat Product Security RHSA-2026:82336 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. The steps to apply the upgraded images are different depending on the installation plan approval policy you used when installing the cert-manager Operator for Red Hat OpenShift. - If t…
Vendor fix Red Hat Product Security RHSA-2026:70870 · 4 productsFor OpenShift Container Platform 4.21 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.21/html/relea…
Vendor fix Red Hat Product Security RHSA-2026:68349 · 4 productsFor OpenShift Container Platform 4.18 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/relea…
Vendor fix Red Hat Product Security RHSA-2026:66521 · 4 productsFor OpenShift Container Platform 4.22 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.22/html/relea…
Vendor fix Red Hat Product Security RHSA-2026:61314 · 4 productsBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258

Advisories and patches

github.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionpoc2026-04-08
OpenCVESSVC decisionpoc—
CNACVSS 3.17.5read 2026-10-23
CNAweakness (CWE)CWE-770read 2026-10-23
FIRST EPSSEPSS score0.9 %2026-10-22
OSVaffected packages—
Microsoft MSRCadvisory—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2026-04-07
Last Modified: 2026-09-11
NVD status: Modified
MSRC Title: OpenTelemetry-Go multi-value `baggage` header extraction causes excessive allocations (remote dos amplification)

Frequently asked questions

What is CVE-2026-29181?

Is CVE-2026-29181 actively exploited?

A proof-of-concept exploit exists for CVE-2026-29181, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-29181?

CVE-2026-29181 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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