How severe is CVE-2026-54285?

CVE-2026-54285 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-54285?

CVE-2026-54285 affects the following packages: @opentelemetry/core (npm). Ecosystems affected: npm.

How do I fix CVE-2026-54285?

Update @opentelemetry/core to 2.8.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54285 is resolved across your whole dependency graph.

How do I detect CVE-2026-54285 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @opentelemetry/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-54285 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-54285 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-54285 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-54285?

CVE-2026-54285 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 33th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-54285?

CVE-2026-54285 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-54285 published, and has it been updated?

CVE-2026-54285 was published on June 22, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2026-54285 — @opentelemetry/core

MEDIUM

CVE-2026-54285 is a medium-severity (CVSS 5.3) CWE-770 vulnerability in @opentelemetry/core. A fix is available for @opentelemetry/core — see the affected versions and patch details below.

opentelemetry-js: Unbounded memory allocation in W3C Baggage propagation

Also known asGHSA-8988-4f7v-96qf

Published

Jun 22, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-54285.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

2Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@opentelemetry/corenpm

89.1Mdownloads / week

Description

Overview

W3CBaggagePropagator.extract() in @opentelemetry/core does not enforce size limits when parsing inbound baggage HTTP headers. The W3C Baggage specification recommends a maximum of 8,192 bytes and 180 entries; these limits were only enforced on the outbound (inject()) path, not on the inbound (extract()) path. Parsing oversized baggage causes memory allocation proportional to the header size without any cap.

Impact

The practical availability impact for most Node.js deployments is limited. Node.js enforces a default --max-http-header-size of 16,384 bytes on the total combined size of all HTTP headers, constraining what an external attacker can deliver before the propagator is reached. Additionally, the header is already in memory (parsed by the HTTP layer) by the time it reaches the propagator - the additional allocation is the overhead of splitting into entry objects, not an unbounded read.

The risk is higher when transport-layer limits are absent - e.g., non-HTTP transports (messaging systems, custom TextMapGetter implementations) or deployments that have raised --max-http-header-size.

Remediation

Update @opentelemetry/core to version 2.8.0 or later. The fix enforces limits consistent with the W3C Baggage specification at the propagator level:

Maximum total baggage size: 8,192 bytes
Maximum number of entries: 180
Maximum per-entry size: 4,096 bytes

Headers that exceed these limits are truncated at the point the limit is reached.

Workarounds

Ensure header size limits are configured at the server or gateway level. The default Node.js HTTP header limit (16 KB) mitigates external attack vectors independently of this fix. For non-HTTP transports receiving baggage from untrusted sources, validate input size before passing it to the propagator.

References

Credit

Reported by tonghuaroot.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@opentelemetry/core`	all versions	2.8.0`npm install @opentelemetry/core@2.8.0`

Affected Products

1 product · 1 configurations

Application

opentelemetryopentelemetry

< 2.8.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @opentelemetry/core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @opentelemetry/core to 2.8.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54285 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Red Hat products ship @opentelemetry/core as a transitive dependency in several components, but the vulnerable W3CBaggagePropagator.extract() code path has limited practical impact. Node.js enforces a default --max-http-header-size of 16,384 bytes, which caps the total size of all HTTP headers before they reach the…

Workaround published by Red Hat

Ensure HTTP header size limits are configured at the server or gateway level. The default Node.js HTTP header limit (16 KB) mitigates external attack vectors independently of this fix. For non-HTTP transports receiving baggage from untrusted sources, validate input size before passing it to the propagator.

Source: Red Hat security advisory for CVE-2026-54285 (CC BY 4.0)

Frequently Asked Questions

## Overview `W3CBaggagePropagator.extract()` in `@opentelemetry/core` does not enforce size limits when parsing inbound `baggage` HTTP headers. The W3C Baggage specification recommends a maximum of 8,192 bytes and 180 entries; these limits were only enforced on the outbound (`inject()`) path, not on the inbound (`extract()`) path. Parsing oversized baggage causes memory allocation proportional to the header size without any cap. ## Impact The practical availability impact for most Node.js deployments is limited. Node.js enforces a default `--max-http-header-size` of 16,384 bytes on the tota