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.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
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
Which versions are affected by CVE-2026-54285?
2 open source packages ship an affected version, including @opentelemetry/core. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@opentelemetry/core npm | All versions | 2.8.0 |
@opentelemetry/core npm | All versions | 2.8.0 |
Products include Opentelemetry Opentelemetry.
How do I fix CVE-2026-54285?
Upgrade @opentelemetry/core to 2.8.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
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 OpenTelemetry-Go multi-value `baggage` header extraction causes excessive allocations (remote dos amplification)
- CVE-2023-47108 DoS vulnerability in otelgrpc (uncontrolled resource consumption) due to unbound cardinality metrics
- CVE-2023-45142 OpenTelemetry-Go Contrib has DoS vulnerability in otelhttp due to unbound cardinality metrics
- CVE-2023-43810 opentelemetry-instrumentation Denial of Service vulnerability due to unbound cardinality metrics
- CVE-2026-39883 opentelemetry-go: BSD kenv command not using absolute path enables PATH hijacking
Sources
Also known as CLEANSTART-2026-VP69884, CLEANSTART-2026-YW31790, CLSA-2026-1791404287, CLSA-2026-1791409515, CLSA-2026-1791413402, CLSA-2026-1791413854 and 32 more.