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Response snapshot Oct 27, 2026, 23:56 UTC

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VulnerabilityCVE-2026-116694

OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation

JaegerPropagator.extract() in opentelemetry-propagator-jaeger did not enforce limits when extracting inbound uberctx-* baggage headers. Attacker-controlled baggage could cause unnecessary CPU work and short-lived heap allocations while processing more data than the propagator should accept.

At a glance

Exploited
Not known
Severity
6.3 Medium (CVSS 4.0)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: opentelemetry-propagator-jaeger: 1.45.0. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-f5m9-jfrj-jjj7 (opens a new tab)

What happened

Summary

JaegerPropagator.extract() in opentelemetry-propagator-jaeger did not enforce limits when extracting inbound uberctx-* baggage headers. Attacker-controlled baggage could cause unnecessary CPU work and short-lived heap allocations while processing more data than the propagator should accept.

Impact

Services that enable the optional Jaeger propagator and accept untrusted inbound propagation headers may experience increased per-request resource usage. This can contribute to denial-of-service risk when transport-level limits are absent or configured above the baggage limits.

Continue reading

The practical impact for most Python web deployments is limited. The package must be installed separately, and the Jaeger propagator is not enabled by the default OpenTelemetry Python configuration.

Common Python web servers also constrain request headers before they reach the propagator:

- Gunicorn allows a maximum of 100 request-header fields and 8,190 bytes per field by default. - Uvicorn’s h11 implementation limits its incomplete-event buffer to 16,384 bytes by default.

The risk is higher for non-HTTP transports, custom TextMapGetter implementations, or deployments where server and gateway limits have been increased or disabled.

The impact is limited to availability. This issue does not expose or modify telemetry data and does not allow code execution.

Patches

Versions of opentelemetry-propagator-jaeger earlier than 1.45.0 are affected.

Upgrade opentelemetry-propagator-jaeger to version 1.45.0 or later.

Version 1.45.0 limits extraction to 180 entries and 8,192 total bytes and skips entries larger than 4,096 bytes.

Credit

tonghuaroot

Affected package ranges reported by GitHub: opentelemetry-propagator-jaeger: <= 1.44.0

Scores and how they were measured

CVSS base severity

6.3

Version 4.0As of

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-f5m9-jfrj-jjj7 (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-f5m9-jfrj-jjj7, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 27). OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation (CVE-2026-116694). https://kevwire.com/record/CVE-2026-116694

MLA

"OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation (CVE-2026-116694)." KEVWire, 27 Oct. 2026, kevwire.com/record/CVE-2026-116694.

Chicago

KEVWire. "OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation (CVE-2026-116694)." Last modified October 27, 2026. https://kevwire.com/record/CVE-2026-116694.

Evidence summary (plain text)

OpenTelemetry Python: Unbounded memory allocation in Jaeger baggage propagation (Oct 27, 2026).
JaegerPropagator.extract() in opentelemetry-propagator-jaeger did not enforce limits when extracting inbound uberctx-* baggage headers. Attacker-controlled baggage could cause unnecessary CPU work and short-lived heap allocations while processing more data than the propagator should accept.

Services that enable the optional Jaeger propagator and accept untrusted inbound propagation headers may experience increased per-request resource usage. This can contribute to denial-of-service risk when transport-level limits are absent or configured above the baggage limits.
CVSS 6.3 (version 4.0; evidence as of Oct 27, 2026; https://github.com/advisories/GHSA-f5m9-jfrj-jjj7).
Sources:
GitHub-reviewed advisory GHSA-f5m9-jfrj-jjj7: https://github.com/advisories/GHSA-f5m9-jfrj-jjj7
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-116694.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 23:40 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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