# CVE-2026-54285: opentelemetry-js: Unbounded memory allocation in W3C Baggage propagation > Attackers can cause denial of service by sending oversized W3C Baggage headers, leading to unbounded memory allocation in the OpenTelemetry JavaScript client. - **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 22 Jun 2026 - **Updated:** 23 Jun 2026 - **Also known as:** CLEANSTART-2026-VP69884, CLEANSTART-2026-YW31790, CLSA-2026-1791404287, CLSA-2026-1791409515, CLSA-2026-1791413402, CLSA-2026-1791413854, CLSA-2026-1791444115, CLSA-2026-1791444187, CLSA-2026-1791444279, CLSA-2026-1791453398, CLSA-2026-1791454221, CLSA-2026-1791456138, CLSA-2026-1793201463, CLSA-2026-1793205230, CLSA-2026-1793267873, ECHO-0b54-337c-5581, GHSA-8988-4f7v-96qf, MINI-29mq-fx9v-q3hf, MINI-3wpq-mg66-p3h3, MINI-488g-jwfq-87qc, MINI-48cm-hpf5-prxj, MINI-4fjj-v3xm-8whx, MINI-4fvq-ppmm-7q8q, MINI-4v3c-hjw3-p27m, MINI-5vgv-8f72-c3gp, MINI-66c7-hxr9-99cr, MINI-66x7-v5f7-qm5w, MINI-6qh4-fqp7-xvcj, MINI-8h52-p78p-cm9r, MINI-c844-fg9j-2vjm, MINI-fpg5-675j-whjw, MINI-gvf8-x6xh-299w, MINI-p5qp-9mpq-r8xw, MINI-rvfr-3x3g-w9w3, MINI-vw77-qfhv-f8pj, MINI-w59w-34gx-7qcv, MINI-xjw2-9jr9-f54r, ROOT-APP-NPM-CVE-2026-54285 ## What is CVE-2026-54285? CVE-2026-54285 is a medium-severity denial of service vulnerability in open-telemetry opentelemetry-js, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description opentelemetry-js is the OpenTelemetry JavaScript Client. Prior to 2.8.0, 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. This vulnerability is fixed in 2.8.0. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling) ## Which versions are affected by CVE-2026-54285? 2 open source packages ship an affected version, including @opentelemetry/core. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `@opentelemetry/core` | npm | All versions | 2.8.0 | | `@opentelemetry/core` | npm | All versions | 2.8.0 | Products: Opentelemetry Opentelemetry. ## How do I fix CVE-2026-54285? Upgrade @opentelemetry/core to 2.8.0 or later. ## Is CVE-2026-54285 being exploited? There is no known exploitation of CVE-2026-54285 in the wild and no public exploit code. ## Other vulnerabilities in open-telemetry opentelemetry-js - [CVE-2026-29181](https://insights.sbomify.com/CVE-2026-29181/): OpenTelemetry-Go multi-value `baggage` header extraction causes excessive allocations (remote dos amplification) (high 7.5) - [CVE-2023-47108](https://insights.sbomify.com/CVE-2023-47108/): DoS vulnerability in otelgrpc (uncontrolled resource consumption) due to unbound cardinality metrics (high 7.5) - [CVE-2023-45142](https://insights.sbomify.com/CVE-2023-45142/): OpenTelemetry-Go Contrib has DoS vulnerability in otelhttp due to unbound cardinality metrics (high 7.5) - [CVE-2023-43810](https://insights.sbomify.com/CVE-2023-43810/): opentelemetry-instrumentation Denial of Service vulnerability due to unbound cardinality metrics (high 7.5) - [CVE-2026-39883](https://insights.sbomify.com/CVE-2026-39883/): opentelemetry-go: BSD kenv command not using absolute path enables PATH hijacking (high 7.3) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-54285 and fix it if it is affected. What it is: CVE-2026-54285 is a medium-severity denial of service vulnerability in open-telemetry opentelemetry-js, published on 22 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-54285 in the wild and no public exploit code. Affected packages and fixed versions: - @opentelemetry/core (npm): affected all versions; fixed in 2.8.0 - @opentelemetry/core (npm): affected all versions; fixed in 2.8.0 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-54285/ (Markdown: https://insights.sbomify.com/CVE-2026-54285/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54285 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54285 - OSV: https://osv.dev/vulnerability/CVE-2026-54285 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-54285/ Summaries are generated and may contain mistakes; the official description above is the record.