LiveActive security incident?Get immediate response
CVE Record

CVE-2026-29181: OpenTelemetry-Go multi-value `baggage` header extraction causes excessive allocations (remote dos amplification)

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.

HighCVSS 7.5Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A remote attacker can make affected Go services consume disproportionate CPU and memory by sending repeated baggage headers. This can reduce availability or contribute to service outages. The flaw affects OpenTelemetry-Go 1.36.0 through 1.40.0 and is fixed in 1.41.0.

Executive priority

Prioritize internet-facing and availability-critical services. The issue is remotely reachable, unauthenticated, and availability-impacting, but the supplied sources do not establish active exploitation. Accelerate dependency inventory and upgrade affected deployments to 1.41.0 or later.

Technical view

OpenTelemetry-Go extracts each baggage header field-value separately, enforcing the 8,192-byte parsing limit per value rather than across all values. Aggregating members from many values can therefore cause excessive allocations and CPU use. CVSS 3.1 rates the resulting unauthenticated network denial of service at 7.5.

Likely exposure

Exposure is most likely where a service uses OpenTelemetry-Go 1.36.0 through 1.40.0 and extracts attacker-controlled baggage headers from inbound requests. Services not using an affected version or not processing such headers are not established as exposed by the supplied evidence.

Exploitation context

The source bundle provides no evidence of active exploitation and marks the CVE as absent from KEV. That does not prove exploitation has never occurred. Exploitation requires network access to a service that processes untrusted, multi-value baggage headers with an affected library version.

Researcher notes

CWE-770 applies because insufficient aggregate resource limits permit uncontrolled consumption. The important boundary is aggregate processing across repeated header values, not merely the documented per-value size limit. The supplied evidence does not quantify request volume, practical outage thresholds, or product-specific exposure beyond OpenTelemetry-Go.

Mitigation direction

  • Upgrade OpenTelemetry-Go to version 1.41.0 or later.
  • Identify applications carrying the affected module directly or transitively.
  • Rebuild and redeploy affected services after updating the dependency.
  • Consult OpenTelemetry and downstream vendor guidance for supported remediation details.

Validation and detection

  • Record the resolved OpenTelemetry-Go version in each deployed application.
  • Confirm no deployed artifact resolves OpenTelemetry-Go between 1.36.0 and 1.40.0.
  • Verify whether internet-facing request paths extract inbound baggage headers.
  • Monitor CPU, memory allocations, latency, and availability for unexplained spikes.
  • Use controlled defensive testing to confirm resource use remains bounded after upgrading.
Prepared
Confidence
high
Sources
3

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-770: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-29181 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
7Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: pocAutomatable: yesTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6GitHub_M
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2026-29181Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Made public.

  3. CVE publishedCVE Program

    The CVE record was published.

  4. ADP timelineredhat-SADP

    Reported to Red Hat.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
redhat-SADPgithub.com/open-telemetry/opentelemetry-go: OpenTelemetry-Go: Denial of Service via crafted multi-value baggage headers
other:Red Hat severity ratingcvssV3_1
  • 2026-04-07T21:01:21.484Z: Reported to Red Hat.
  • 2026-04-07T20:29:13.933Z: Made public.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
open-telemetryopentelemetry-go>= 1.36.0, < 1.41.0Listed
Weakness

CWE details

CWE-770

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-770 · source CWE mapping

Allocation of Resources Without Limits or Throttling

Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs